diff --git a/CMakeLists.txt b/CMakeLists.txt
index 14c5f0e..2287c64 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -26,6 +26,7 @@ add_custom_command(
 	COMMAND mkdir -p generated/include && sh update_levels.sh
 	WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
 	DEPENDS update_levels.sh compile_levels.py
+		editor/levels/
 		editor/levels/0.lvl
 		editor/levels/1.lvl
 		editor/levels/2.lvl
@@ -43,7 +44,9 @@ add_custom_command(
 		editor/levels/14.lvl
 		editor/levels/15.lvl
 		editor/levels/16.lvl
-		editor/levels/17.lvl)
+		editor/levels/17.lvl
+		editor/levels/18.lvl
+		editor/levels/19.lvl)
 
 set(SOURCES
 	src/collide.c
@@ -51,6 +54,8 @@ set(SOURCES
 	src/main.c
 	src/menu.c
 	src/save.c
+	src/util.c
+	src/replace.c
 	generated/setlevel.c
 	generated/times.c)
 
@@ -87,6 +92,6 @@ fxconv_declare_assets(${ASSETS} ${ASSETS_fx} ${ASSETS_cg} WITH_METADATA)
 add_executable(${PROJECT_NAME} ${SOURCES} ${ASSETS} ${ASSETS_${FXSDK_PLATFORM}})
 target_compile_options(${PROJECT_NAME} PRIVATE ${FLAGS})
 target_link_libraries(${PROJECT_NAME} Gint::Gint)
-
+target_link_options(${PROJECT_NAME} PRIVATE -Wl,-Map=map)
 generate_g3a(TARGET ${PROJECT_NAME} OUTPUT "${PROJECT_NAME}.g3a"
 	NAME "${PROJECT_NAME}" ICONS assets-cg/icon-uns.png assets-cg/icon-sel.png)
diff --git a/compile_levels.py b/compile_levels.py
index 74bbb85..ab12f5c 100755
--- a/compile_levels.py
+++ b/compile_levels.py
@@ -7,8 +7,7 @@ while 1:
     try:
         lv = open(f"editor/levels/{ids}.lvl","r")
         ide = lv.readlines()
-        if ide[1]!='\n':
-            save.write(f"case {ids}:\nmemcpy(level,\"{str(ide[0][:-2])}\",350);\n*appear={ide[1][:-1]};\n*disappear={ide[2]};\n*nbswitch={ide[3]};\nbreak;\n")
+        save.write(f"case {ids}:\nmemcpy(level,\"{str(ide[0][:-2])}\",350);\n*appear={ide[1][:-1]};\n*disappear={ide[2][:-1]};\n*nbswitch={ide[3]};\nbreak;\n")
         ids+=1
     except FileNotFoundError:
         lv.close()
@@ -30,13 +29,13 @@ y+=16;}i++;}}\n\
 void set_gravity(int id_level, char *default_gravity){\n\
 switch(id_level){")
 ids = 0
-gravity = 0
+gravity = -1
 while 1:
     try:
         lv = open(f"editor/levels/{ids}.lvl","r")
         ide = lv.read()
-        if ide[350]=="6": gravity=0
-        else: gravity = 1
+        if ide[350]=="6": gravity=1
+        else: gravity = -1
         save.write(f"case {ids}:\n*default_gravity = {gravity};\nbreak;\n")
         ids+=1
     except FileNotFoundError:
diff --git a/editor/AST3generator.py b/editor/AST3generator.py
index 9d0959b..40296d0 100755
--- a/editor/AST3generator.py
+++ b/editor/AST3generator.py
@@ -107,12 +107,15 @@ def place():
     fenetre.blit(levelgr, (10, 60))
     fenetre.blit(timeapp, (55, 10))
     fenetre.blit(timedisa, (140, 10))
-    fenetre.blit(nbswitchfont, (370, 10))
+    if "z" in str(grille):
+        fenetre.blit(nbswitchfont, (370, 10))
     if id_level==0 : fenetre.blit(font.render("NIVEAU DE TEST",1,(0,180,255)), (600,10))
     pygame.display.flip()
 
 def write():
+    global nbswitch
     f = open(f"editor/levels/{id_level}.lvl","w+")
+    if "z" not in str(grille): nbswitch = 1
     f.write(str(grille).replace("]","").replace("(","").replace(")","").replace("'","").replace("[","").replace(" ","").replace(",","")+f"{gravityid}\n{app}\n{disa}\n{nbswitch}")
     f.close()
 
@@ -130,7 +133,7 @@ id_level = 0
 gravityid = 6
 disa = 10
 app = 13
-nbswitch = -1
+nbswitch = 1
 lock=""
 tab = 0
 
@@ -190,12 +193,12 @@ while securite==False:
                 disa-=1
                 write()
                 place()
-            if carac == "t":
+            if carac == "t" and "z" in str(grille):
                 nbswitch+=1
                 write()
                 place()
-            if carac == "g":
-                if nbswitch >= 0: nbswitch-=1
+            if carac == "g" and "z" in str(grille):
+                if nbswitch > 0: nbswitch-=1
                 write()
                 place()
             if carac == "a":
diff --git a/editor/levels/0.lvl b/editor/levels/0.lvl
index e739900..f64b70d 100755
--- a/editor/levels/0.lvl
+++ b/editor/levels/0.lvl
@@ -1,4 +1,4 @@
 11111111111111111111000111000000000000000000000001100000000000000000000000110e00000b0000l000S000000111111aaaaaaa11111111111111ddd1ddddddd1mmm1000000011ddd111111111mmm1000000011ddd111111111ccc101BB00011ddd1ddddddd1ccc10i00000111111aaaaaaa111110i000001100000000000030010i0000011000000000000300h0i1BBB111s000K00000k0300h0i0000011111111ddd1111111111000116
-13
-10
--1
\ No newline at end of file
+6
+9
+1
\ No newline at end of file
diff --git a/editor/levels/1.lvl b/editor/levels/1.lvl
index bceeb37..dad93ab 100755
--- a/editor/levels/1.lvl
+++ b/editor/levels/1.lvl
@@ -1,4 +1,4 @@
 10011111111dddd1111111111000111100000000000000000000011110011111111ddd100001111111001dd000ddddd111111111111001dd0t0ddddddddd11000001001dd000ddddddddd11000001001aaaaaaaaaaaaaa110s00010010000000000000e11d1100100100000000000aaa11111001001000000000ddddd1111100100100000000011111100010000010000000003000000001000001000K0000030k00010011111111111111111111116
-13
+11
 10
--1
\ No newline at end of file
+1
\ No newline at end of file
diff --git a/editor/levels/10.lvl b/editor/levels/10.lvl
index b5bd444..42b8a2c 100755
--- a/editor/levels/10.lvl
+++ b/editor/levels/10.lvl
@@ -1,4 +1,4 @@
 11111111t133111111100011111111111133311111110K01111100000100111111111000111110s00010i11111100000001111d110K10i11111d000000011111110K10i1111a001BBBBB11110000010i111d0a010000011110000010i11a03011d0ddd1111001ddd0i1d0a0d110000011110000000i0a30111100e00111100000k0130ad11110aa001111dd000001031111111ddd11111111111B1001111111aaa11111111111010011111110001116
 13
 10
--1
\ No newline at end of file
+1
\ No newline at end of file
diff --git a/editor/levels/11.lvl b/editor/levels/11.lvl
index b9ebdbe..8602403 100755
--- a/editor/levels/11.lvl
+++ b/editor/levels/11.lvl
@@ -1,4 +1,4 @@
 1ddddddddddd11dddddddddd11dddddddddd00000dd3aaa11i1dd111100000000000030000i1dd000000000001110003000i1d000001111100K000003000i1d00000S00k0000000003aBB110s000100000ddd011103atl11111331ddddddddddddddd1111ddd001dddddddd11d0S0ddd11ddd00d1dd11d000300000dd11ddd000000000000300000dd11dddaaa00000000d3S00e0dd11dddddd00S0d111d3d000ddd11ddddddddddddddddddddddd16
 13
 10
--1
\ No newline at end of file
+1
\ No newline at end of file
diff --git a/editor/levels/12.lvl b/editor/levels/12.lvl
index 275fdc9..a347bcc 100755
--- a/editor/levels/12.lvl
+++ b/editor/levels/12.lvl
@@ -1,4 +1,4 @@
 1111111111010001dd11111110000001000013331001000000000000100t01000h0010000001111iB111111000h0013311111e00ik11d111000300300000d10ddi011d0010003003000s0d10aai01000010001hh1hh11111000i01h1h1100010010000011dd0i000000h00010010001a11aa01dd0dd110001001000h0110001dd1d1110S0100100010110000S0S0001ddd100h0001Kd100000S0S001111100h00011111111dddd10h00011111111116
 13
 10
--1
\ No newline at end of file
+1
\ No newline at end of file
diff --git a/editor/levels/13.lvl b/editor/levels/13.lvl
index 3b4ff32..8e1b788 100755
--- a/editor/levels/13.lvl
+++ b/editor/levels/13.lvl
@@ -1,4 +1,4 @@
 11111111111111111111111111ddddddddd0S00ddddddddddd1ddddaaaaa000000ddddddddd1ddd00S000000e0ddd0dddddd1dd000000ddddddd00000dddd1daaaa00dd11100S00S000ddd10000000d00000000000S00dd10K000h0d00001100000000dd1111000ddd000000S0d0h00dd1ddd000dd000dd000ddd000dd1dddhhdd000ddddddddd000dd1ddb00S0000100000dd0000dd1dtb00000011s000000000ddd111111d11111111111111dddd6
 13
 10
--1
\ No newline at end of file
+1
\ No newline at end of file
diff --git a/editor/levels/14.lvl b/editor/levels/14.lvl
index 74a3c39..08988b6 100755
--- a/editor/levels/14.lvl
+++ b/editor/levels/14.lvl
@@ -1,4 +1,4 @@
 1111111111111ddd11iK1d00100000d111000000011it1d00000000d100000000011i31110011100d13331110e011ihhh11100000d100011111111i00000000000d100000011111i00111011100d1000000000011000s111111111000000000011dd0001hk001111i00Sddd001dddd00hh0000001i000111000aad1ddhddd0000000001110000001111111dd0000000111000000001111111dd000011110000000001111111111111111ddd13100017
 13
 10
--1
\ No newline at end of file
+1
\ No newline at end of file
diff --git a/editor/levels/15.lvl b/editor/levels/15.lvl
index e2e480f..cacb12e 100755
--- a/editor/levels/15.lvl
+++ b/editor/levels/15.lvl
@@ -1,4 +1,4 @@
 i011100dd1111dddm111ddmd1i01d1000000010S0011100S01i01d100000001000000000001i01d1cc111001hh1c11111001i01ddddddi00i000bddd00001i01dd1133i00i000lddd000K1100000000i00i00001d110011300000000i00100331d100003300000010i001s03t1d1000031111100hki0011111ddd1BB1110S01hh11100m0000aaa0000110001001d100m000000000001100e1001d100m0aaa000aaa0110d11001111111ddddddddd116
-13
-10
--1
\ No newline at end of file
+4
+7
+1
\ No newline at end of file
diff --git a/editor/levels/16.lvl b/editor/levels/16.lvl
index 6a13da1..4ac0d65 100755
--- a/editor/levels/16.lvl
+++ b/editor/levels/16.lvl
@@ -1,4 +1,4 @@
 11111dddd100d110111111331000000000000d1d0000dd10s0111d00000000K1d10000d11111ddddd11ddhh1dddd000dddd11100Sh00dd00000dd00000001i0000000dd000000d0000S001i01100d0dd00d000dd0000001i0d00Sd0dd00dd10ddhh00l01i0ddddd0dd00ddi0d00000001iBBBdd0011aaddi0d0S00d0011000dd000300ddi0d0000d00110mmdd000d00ddi0dd00dd0011emtdddddd00ddi0ddddddkk1111111111100111Bdddd110016
-13
+14
 10
--1
\ No newline at end of file
+1
\ No newline at end of file
diff --git a/editor/levels/17.lvl b/editor/levels/17.lvl
index 89884d0..977b885 100644
--- a/editor/levels/17.lvl
+++ b/editor/levels/17.lvl
@@ -1,4 +1,4 @@
 101111110111111111100111110dS00d00000001111100111110aaa0d00000K010000001111100h00d0S0000010ddaaa1111100000ddd1111110ddddd1111111a00000S1e3s00100S0111100z0000000111dda100k0100000z000000000ddddd00001000111ddaaaaa000000000101001100Saddddd0000000001010011000000aa11111111111110011000a000003000000010000011000a0a0003010000t100000110111111011111111110011117
 13
 10
-18
\ No newline at end of file
+19
\ No newline at end of file
diff --git a/editor/levels/18.lvl b/editor/levels/18.lvl
new file mode 100644
index 0000000..f670ad6
--- /dev/null
+++ b/editor/levels/18.lvl
@@ -0,0 +1,4 @@
+111111110011ddd111111111110000001000S000S0d000000110000001000000000d0000s0111mmm101aaa000000d00BBB31100m01010a0000000d00B0Bb1100m01h10a00dKdhi0i0BBB011d0m01h10a00d0d00i00B0B011d0001h10000dSd00i00d00011d00d1h10000ddd00iBBd0t01h000d101dddd11100000d000h1000d1011111111331111111130000100000ddd000000100003000110000000000000k10e00111111110011111ddd11111116
+8
+10
+1
\ No newline at end of file
diff --git a/editor/levels/19.lvl b/editor/levels/19.lvl
new file mode 100644
index 0000000..acb5a4c
--- /dev/null
+++ b/editor/levels/19.lvl
@@ -0,0 +1,4 @@
+11111111111111111111111111000000000000000000000001i000000000000000000000001i0000iiiii11i11iiiii00001i000000000000000000000001i00S000000000000000000001i000000000000000000000001i000011111111111111100001i000000000000000000000001i000000000000000000000001i0000iiiiiiiiiiiiiii00001i000000000000000000000001i00s00000000000000000e00111111iiiiiiiiiiiiiii111116
+8
+10
+1
\ No newline at end of file
diff --git a/editor/levels/2.lvl b/editor/levels/2.lvl
index 2690b13..b4485cb 100755
--- a/editor/levels/2.lvl
+++ b/editor/levels/2.lvl
@@ -1,4 +1,4 @@
 1dddddd100111111111111111000000000011111000000000000000000l01100c00000000001aaaaaaa111100c00000000011dddddddddd1001aaaaaaaaa11cccccccccc1001ddddddddd1000000000001331000000aa000000000000s10e1k0000000001ccccccccc111111111113311100000000011001000000000110000000001100b0000000001100000000011t0b00000000011000K0000011111aaaaaaaaa1111111110011111ddddddddd16
 13
-10
--1
\ No newline at end of file
+2
+1
\ No newline at end of file
diff --git a/editor/levels/3.lvl b/editor/levels/3.lvl
index adf6609..65da0ed 100755
--- a/editor/levels/3.lvl
+++ b/editor/levels/3.lvl
@@ -1,4 +1,4 @@
 11001111111001111111111111000111dddd000000000100013000111dddd00000000010003300000000dd11111000010e03100000000dd03a01000011111111110000dd03a01000000001100s1dd00ddt3a0100000000110001dd00dd1110100000000110001dd0Kdd00001ddd000ddd10001dd00dd00001111100ddd10001dd00dd00001000000ddd30001dd0000000010k000000330001dd0000000010000000031d001111111001111111111117
 13
 10
--1
\ No newline at end of file
+1
\ No newline at end of file
diff --git a/editor/levels/4.lvl b/editor/levels/4.lvl
index a98c35c..7708628 100755
--- a/editor/levels/4.lvl
+++ b/editor/levels/4.lvl
@@ -1,4 +1,4 @@
 11111111111011111dddd1111100001dd0000dd100000000011s0001dd0d11dd10000000001111001dd0d111dd00111100011dd001dt0d10000001dd100011dd001d11d10000001dd100011dd00dd11110011111dd100011dd00000000001dddddd100011dd1111dbd1111ddd111100011ddddddd0dd1d1ddd100000011ddddddd0000d1ddd1e0000011ddddddd1110d1ddd111cccc11dddddddddd0d1ddd111dddd111111111111011111111111116
 13
-10
--1
\ No newline at end of file
+7
+1
\ No newline at end of file
diff --git a/editor/levels/5.lvl b/editor/levels/5.lvl
index d376b0c..4954ca5 100755
--- a/editor/levels/5.lvl
+++ b/editor/levels/5.lvl
@@ -1,4 +1,4 @@
 000000000000000000000000000000000000000000000000t000000000000000000000000000011dd111111111111111110000100000100000010000001000011cc001s0000d00000001000010000e111dd0100000dd100001001111000d0000000dd100001000001000111d000ddd1000010000000000000000ddd1000011111111111d111B11111000000000000000000000000000000000000000000000000000000000000000000000000000006
 13
-10
--1
\ No newline at end of file
+6
+1
\ No newline at end of file
diff --git a/editor/levels/6.lvl b/editor/levels/6.lvl
index 7fcc797..0998bf8 100755
--- a/editor/levels/6.lvl
+++ b/editor/levels/6.lvl
@@ -1,4 +1,4 @@
 10001011111011111111111111000101dd10001111dddd11110000101dd10001000000000001111101dd1aaa1000ccccddd110s00010013331000000000011dddd110010001mmmdd00000100000000010e010t0dd00000011111100011111d1dddddd1111k00000001d000111001111111111111101d00000000000111000010000100000000000000010K010000100011100000011110001000010001110000dd11110001011111011111111111117
-13
-10
--1
\ No newline at end of file
+5
+9
+1
\ No newline at end of file
diff --git a/editor/levels/7.lvl b/editor/levels/7.lvl
index a45bc7b..4c98595 100755
--- a/editor/levels/7.lvl
+++ b/editor/levels/7.lvl
@@ -1,4 +1,4 @@
 111001111111100i0d0011111100000111ddd000i0d0000001100000000000000itd00000e1111111ddd111111111111111100000000000000000h00d0000111111111dd111110100d000110001100000000010100d0001000011000000000i0d00d0000000000000000000i0d00d00001111dd111100000ild00111111000011111ddd00i0d0011111d000011111ddd00i0d0011111d0s0011111ddd00i0d0011111111001111111100i0d00111116
 13
 10
--1
\ No newline at end of file
+1
\ No newline at end of file
diff --git a/editor/levels/8.lvl b/editor/levels/8.lvl
index 438149e..15d0ae4 100755
--- a/editor/levels/8.lvl
+++ b/editor/levels/8.lvl
@@ -1,4 +1,4 @@
 dddddddddddddddddddddddddBBBBBBBBBBBBBBBBBBBBBBBBB100001kk10011111dt0a000011000010010010000d11a00001100001BB100100000000000013000000000010001110000000300000000001aaaaaa0000000111111000001000000001111110dd00000001000000001000110000000a001BBBd00a0100013000000000010001000010003300s000000010K0100001e003aaBBBBBBBBBBBBBBBBBBBaaaaddddddddddddddddddddddddd6
 13
 10
--1
\ No newline at end of file
+1
\ No newline at end of file
diff --git a/editor/levels/9.lvl b/editor/levels/9.lvl
index 1374d7f..55230eb 100755
--- a/editor/levels/9.lvl
+++ b/editor/levels/9.lvl
@@ -1,4 +1,4 @@
 00000ddddddd100000000000011111111111111111110011111000000dd1111ddd0K10000b1100111000000100000100000110000100000010000010010011000k111dd101dd00d10000011000110000001000001BBBB011000100011dd1000001dddd01100010ddd1dd1d00dd1011001133310ddd1dd1BBBBB1t00001100000ddd1dd1000001ddd1111s0000ddd1dd10000011111111BBB111aaaaa110001111111100000000000e10000000000006
 13
 10
--1
\ No newline at end of file
+1
\ No newline at end of file
diff --git a/include/collide.h b/include/collide.h
index 4444f13..b732a11 100755
--- a/include/collide.h
+++ b/include/collide.h
@@ -4,3 +4,4 @@ char collide_dead(int x, int y, char level[]);
 char collide_point(int x, int y, char level[], char block);
 char collide_end(int x, int y, char level[]);
 void collide_replace(int x, int y, char level[], char collide, char replace);
+char collide_center(int x, int y, char level[], char block);
diff --git a/include/menu.h b/include/menu.h
index cd6e13d..bbb987d 100755
--- a/include/menu.h
+++ b/include/menu.h
@@ -1,3 +1,6 @@
-char start_menu();
+#pragma once
+
+enum MenuCode { MenuLevelSel, MenuAllMode, MenuTutorial, MenuExit };
+
+enum MenuCode start_menu();
 char speed_menu(int *id_level);
-int round(float num);
diff --git a/include/replace.h b/include/replace.h
new file mode 100644
index 0000000..c3d903a
--- /dev/null
+++ b/include/replace.h
@@ -0,0 +1,2 @@
+void replace_all_block(char a, char b, char level[]);
+void replace_xy_block(int x, int y, char block, char level[]);
\ No newline at end of file
diff --git a/include/util.h b/include/util.h
new file mode 100644
index 0000000..4b0ba63
--- /dev/null
+++ b/include/util.h
@@ -0,0 +1,3 @@
+#pragma once
+
+int round(float num);
diff --git a/src/collide.c b/src/collide.c
index 0eb39f8..eae58b9 100644
--- a/src/collide.c
+++ b/src/collide.c
@@ -1,18 +1,22 @@
 #include "collide.h"
 #include "define.h"
+#include "util.h"
 
 #define DEAD_COLLISION 3 // make collision with the deadly block less effective
 
 char collide(int x, int y, char level[],
              char block) // detect if player is in a block
 {
-	if ((level[(int)(x / 16) + (int)((y + PLAYER_HEIGHT) / 16) * 25] ==
+	if ((level[(int)(x / TILE_HEIGHT) +
+	           (int)((y + PLAYER_HEIGHT) / TILE_HEIGHT) * LEVEL_WIDTH] ==
 	         block ||
-	     level[(int)((x + PLAYER_HEIGHT) / 16) +
-	           (int)((y + PLAYER_HEIGHT) / 16) * 25] == block ||
-	     level[(int)(x / 16) + (int)((y / 16) * 25)] == block ||
-	     level[(int)((x + PLAYER_HEIGHT) / 16) + (int)((y / 16) * 25)] ==
-	         block))
+	     level[(int)((x + PLAYER_HEIGHT) / TILE_HEIGHT) +
+	           (int)((y + PLAYER_HEIGHT) / TILE_HEIGHT) * LEVEL_WIDTH] ==
+	         block ||
+	     level[(int)(x / TILE_HEIGHT) +
+	           (int)((y / TILE_HEIGHT) * LEVEL_WIDTH)] == block ||
+	     level[(int)((x + PLAYER_HEIGHT) / TILE_HEIGHT) +
+	           (int)((y / TILE_HEIGHT) * LEVEL_WIDTH)] == block))
 		return 1;
 	return 0;
 }
@@ -44,7 +48,8 @@ char collide_dead(int x, int y, char level[])
 
 char collide_point(int x, int y, char level[], char block)
 {
-	return (level[(int)(x / 16) + (int)(y / 16) * 25] == block);
+	return (level[(int)(x / TILE_HEIGHT) +
+	              (int)(y / TILE_HEIGHT) * LEVEL_WIDTH] == block);
 }
 
 char collide_end(int x, int y, char level[])
@@ -55,17 +60,32 @@ char collide_end(int x, int y, char level[])
 void collide_replace(int x, int y, char level[], char collide, char replace)
 {
 	if (collide_point(x, y, level, collide)) {
-		level[((x) / 16) + ((y) / 16) * 25] = replace;
+		level[((x) / TILE_HEIGHT) + ((y) / TILE_HEIGHT) * LEVEL_WIDTH] =
+		    replace;
 	}
 	if (collide_point(x + PLAYER_HEIGHT, y, level, collide)) {
-		level[((x + PLAYER_HEIGHT) / 16) + ((y) / 16) * 25] = replace;
+		level[((x + PLAYER_HEIGHT) / TILE_HEIGHT) +
+		      ((y) / TILE_HEIGHT) * LEVEL_WIDTH] = replace;
 	}
 	if (collide_point(x, y + PLAYER_HEIGHT, level, collide)) {
-		level[((x) / 16) + ((y + PLAYER_HEIGHT) / 16) * 25] = replace;
+		level[((x) / TILE_HEIGHT) +
+		      ((y + PLAYER_HEIGHT) / TILE_HEIGHT) * LEVEL_WIDTH] =
+		    replace;
 	}
 	if (collide_point(x + PLAYER_HEIGHT, y + PLAYER_HEIGHT, level,
 	                  collide)) {
-		level[((x + PLAYER_HEIGHT) / 16) +
-		      ((y + PLAYER_HEIGHT) / 16) * 25] = replace;
+		level[((x + PLAYER_HEIGHT) / TILE_HEIGHT) +
+		      ((y + PLAYER_HEIGHT) / TILE_HEIGHT) * LEVEL_WIDTH] =
+		    replace;
 	}
 }
+
+char collide_center(int x, int y, char level[], char block)
+{
+	if (level[(int)((x + round(PLAYER_HEIGHT / 2)) / TILE_HEIGHT) +
+	          (int)((y + round(PLAYER_HEIGHT / 2)) / TILE_HEIGHT) *
+	              LEVEL_WIDTH] == block) {
+		return 1;
+	}
+	return 0;
+}
\ No newline at end of file
diff --git a/src/main.c b/src/main.c
index 2945aac..59f03c7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,3 +1,12 @@
+#include "collide.h"
+#include "define.h"
+#include "drawlevel.h"
+#include "menu.h"
+#include "replace.h"
+#include "save.h"
+#include "setlevel.h"
+#include "times.h"
+#include "util.h"
 #include <gint/clock.h>
 #include <gint/display.h>
 #include <gint/gint.h>
@@ -5,31 +14,67 @@
 #include <gint/std/string.h>
 #include <gint/timer.h>
 
-#include "collide.h"
-#include "define.h"
-#include "drawlevel.h"
-#include "menu.h"
-#include "save.h"
-#include "setlevel.h"
-#include "times.h"
-
 #define VACCELERATION 0.2
 #define HACCELERATION 0.4
 #define MAX_VSPD 9.0
 #define FRICTION 0.2
 
-int main(void);
-void end(unsigned int frame);
+static int callback(volatile int *frame_elapsed);
+static void end(unsigned int frame);
+static void game(int *id_level, char mode, char *type);
 
-char run = 0;
+int main(void)
+{
+	static int run = 0;
+	if (!run) {
+		gint_world_switch(GINT_CALL(restore));
+		run = 1;
+	}
 
-int callback(volatile int *frame_elapsed)
+	char mode = 0;
+	char type = 1;
+	const enum MenuCode valeur = start_menu(&type);
+
+	switch (valeur) {
+	case MenuLevelSel: {
+		int id_level = 1;
+		if (!speed_menu(&id_level)) {
+			mode = 1;
+			game(&id_level, mode, &type);
+		} else
+			main();
+	} break;
+	case MenuAllMode: {
+		int id_level = 1;
+		mode = 0;
+		game(&id_level, mode, &type);
+	} break;
+	case MenuTutorial: {
+		int id_level = 0;
+		mode = 1;
+		game(&id_level, mode, &type);
+	} break;
+	case MenuExit:
+		gint_world_switch(GINT_CALL(savefile));
+		break;
+	}
+	return 0;
+}
+
+static int callback(volatile int *frame_elapsed)
 {
 	*frame_elapsed = 1;
 	return TIMER_CONTINUE;
 }
 
-void game(int *id_level, char mode, char *type)
+static void end(unsigned int frame)
+{
+	draw_end((int)frame, 15, 2);
+	sleep_ms(7000);
+	main();
+}
+
+static void game(int *id_level, char mode, char *type)
 {
 	volatile int frame_elapsed = 1;
 	int timer = timer_configure(TIMER_ANY, 1000000 / FPS,
@@ -41,7 +86,7 @@ void game(int *id_level, char mode, char *type)
 	int framelevel = 0;
 	int player_x = 20, player_y = 20;
 	char level[351];
-	char gravity = 0; // 0 down 1 up
+	char gravity = -1; // 1 down -1 up
 	char check = 1;
 	char blackout = 0;
 	int start_x;
@@ -60,6 +105,7 @@ void game(int *id_level, char mode, char *type)
 	char check_nbswitch = 0;
 	float vspd = 1.0;
 	float hspd = 0.0;
+
 	if (*id_level == 10 && *type != 3)
 		*type = 2;
 	else if (*type != 3)
@@ -69,7 +115,7 @@ void game(int *id_level, char mode, char *type)
 	          &disappear, &nbswitch);
 	player_x = start_x;
 	player_y = start_y;
-	draw_level(level);
+
 	while (game_loop) {
 		while (!frame_elapsed)
 			sleep();
@@ -112,102 +158,78 @@ void game(int *id_level, char mode, char *type)
 				draw_nbswitch(nbswitch);
 			dupdate();
 		}
-
 		pollevent();
 
 		if (keydown(KEY_OPTN)) {
-			level[((player_x + 6) / 16) +
-			      ((player_y + 6) / 16) * 25] = 'd';
+			replace_xy_block(player_x + 6, player_y + 6, 'd',
+			                 level);
 			death_count--;
 		}
-		// Right collision
-		if (keydown(KEY_RIGHT)) {
+
+		// right and left collision
+		if (keydown_any(KEY_RIGHT, KEY_LEFT, 0)) {
+			float hbuff = 0.0;
+			char signe = (keydown(KEY_RIGHT) - keydown(KEY_LEFT));
+			if (collide(player_x, player_y - 1, level, 'i') ||
+			    collide(player_x, player_y + 1, level, 'i')) {
+				hbuff += 0.12;
+			}
 			hspd *= 1 - FRICTION;
-			hspd += (keydown(KEY_RIGHT) - keydown(KEY_LEFT)) *
-				HACCELERATION;
-			if (!collide_solid(player_x + round(hspd) + 1, player_y,
-			                   level))
+			hspd += signe * (HACCELERATION + hbuff);
+			if (!collide_solid(player_x + round(hspd) + signe * 1,
+			                   player_y, level))
 				player_x += round(hspd);
-			else if (!collide_solid(player_x + 1, player_y, level))
-				player_x += 1;
+			else if (!collide_solid(player_x + signe * 1, player_y,
+			                        level))
+				player_x += signe;
 			if (player_x >= 388)
 				player_x = -4;
-		}
-		// Left collision
-		else if (keydown(KEY_LEFT)) {
-			hspd *= 1 - FRICTION;
-			hspd += (keydown(KEY_RIGHT) - keydown(KEY_LEFT)) *
-				HACCELERATION;
-			if (!collide_solid(player_x + round(hspd) - 1, player_y,
-			                   level))
-				player_x += round(hspd);
-			else if (!collide_solid(player_x - 1, player_y, level))
-				player_x -= 1;
 			if (player_x < -9)
 				player_x = 384;
 		} else
 			hspd = 0;
+
 		// Action key
-		if (keydown(KEY_SHIFT) && !check &&
-		    (nbswitch > 0 || nbswitch == -1) &&
+		if (keydown(KEY_SHIFT) && !check && nbswitch > 0 &&
 		    ((collide_solid(player_x, player_y - 1, level) &&
-		      gravity) ||
+		      gravity == -1) ||
 		     (collide_solid(player_x, player_y + 1, level) &&
-		      !gravity))) {
+		      gravity))) {
 			vspd = 1;
-			if (!gravity)
+			if (gravity == -1)
 				gravity = 1;
 			else
-				gravity = 0;
-			if (check_nbswitch && nbswitch != 0) {
+				gravity = -1;
+			if (check_nbswitch && nbswitch > 0) {
 				nbswitch -= 1;
 			}
 			check = 1;
 		} else if (!keydown(KEY_SHIFT) && check)
 			check = 0;
-		// Gravity
-		if (!gravity) {
-			if (!collide_solid(player_x, player_y + (int)vspd + 1,
-			                   level)) {
-				if (vspd < MAX_VSPD)
-					vspd += VACCELERATION;
-				if (collide(player_x + 1, player_y, level, 'i'))
-					vspd += 0.15;
-				if (collide(player_x - 1, player_y, level, 'i'))
-					vspd += 0.15;
-				player_y += (int)vspd;
-			} else if (!collide_solid(
-				       player_x, player_y + (int)vspd, level)) {
-				vspd -= VACCELERATION;
-				player_y += (int)vspd;
-			} else if (!collide_solid(player_x, player_y + 1,
-			                          level)) {
-				vspd = 1;
-				player_y += 1;
-			} else
-				vspd = 1;
-		} else {
-			if (!collide_solid(player_x, player_y - (int)vspd - 1,
-			                   level)) {
-				if (vspd < MAX_VSPD)
-					vspd += VACCELERATION;
-				if (collide(player_x + 1, player_y, level, 'i'))
-					vspd += 0.15;
-				if (collide(player_x - 1, player_y, level, 'i'))
-					vspd += 0.15;
-				player_y -= (int)vspd;
-			} else if (!collide_solid(
-				       player_x, player_y - (int)vspd, level)) {
-				vspd -= VACCELERATION;
-				player_y -= (int)vspd;
-			} else if (!collide_solid(player_x, player_y - 1,
-			                          level)) {
-				vspd = 1;
-				player_y -= 1;
-			} else
-				vspd = 1;
-		}
-		// Collide with red block
+
+		// gravity
+		if (!collide_solid(player_x,
+		                   player_y + ((int)vspd) * gravity + gravity,
+		                   level)) {
+			if (vspd < MAX_VSPD)
+				vspd += VACCELERATION;
+			if (collide(player_x + 1, player_y, level, 'i') ||
+			    collide(player_x - 1, player_y, level, 'i'))
+				vspd += 0.15;
+			player_y += ((int)vspd) * gravity;
+		} else if (!collide_solid(player_x,
+		                          player_y + ((int)vspd) * gravity,
+		                          level)) {
+			vspd -= VACCELERATION;
+			player_y += ((int)vspd) * gravity;
+		} else if (!collide_solid(player_x, player_y + gravity,
+		                          level)) {
+			vspd = 1;
+			player_y += 1 * gravity;
+		} else
+			vspd = 1;
+
+		// Collide with dead block
 		if (collide_dead(player_x, player_y, level)) {
 			vspd = 1;
 			player_x = start_x;
@@ -236,6 +258,7 @@ void game(int *id_level, char mode, char *type)
 			          &gravity, &appear, &disappear, &nbswitch);
 			player_x = start_x;
 			player_y = start_y;
+			check_nbswitch = 0;
 			blackout = 0;
 			double_check = 1;
 			framelevel = 0;
@@ -248,68 +271,40 @@ void game(int *id_level, char mode, char *type)
 				end(frame);
 			}
 		}
-		if (collide(player_x, player_y, level,
-		            'k')) // Collide with key1 = disappearance of blocks
-		{
-			for (int i = 0; level[i] != '\0'; i++) {
-				if (level[i] == '3')
-					level[i] = '0';
-				if (level[i] == 'k')
-					level[i] = '0';
-			}
+		// Collide with key1 = disappearance of blocks
+		if (collide(player_x, player_y, level, 'k')) {
+			replace_all_block('3', '0', level);
+			replace_all_block('k', '0', level);
 		}
-		if (collide(player_x, player_y, level,
-		            'K')) // Collide with key2 = appearance of blocks
-		{
-			for (int i = 0; level[i] != '\0'; i++) {
-				if (level[i] == 'a')
-					level[i] = '4';
-				if (level[i] == 'K')
-					level[i] = '0';
-			}
+		// Collide with key2 = appearance of blocks
+		if (collide(player_x, player_y, level, 'K')) {
+			replace_all_block('a', '4', level);
+			replace_all_block('K', '0', level);
 		}
-		if (collide(player_x, player_y, level, 't') &&
-		    !check_coin) // Collide with coin
-		{
-			for (int i = 0; level[i] != '\0'; i++) {
-				if (level[i] == 't') {
-					level[i] = '0';
-					break;
-				}
-			}
+		// Collide with coin
+		if (collide(player_x, player_y, level, 't') && !check_coin) {
+			replace_all_block('t', '0', level);
 			check_coin = 1;
 			coin++;
 		}
-		if (collide(player_x, player_y, level,
-		            'b')) // Collide with blackout block
-		{
-			for (int i = 0; level[i] != '\0'; i++) {
-				if (level[i] == 'b') {
-					level[i] = '0';
-					break;
-				}
-			}
+		// Collide with blackout block
+		if (collide(player_x, player_y, level, 'b')) {
+			replace_all_block('b', '0', level);
 			blackout = 1;
 		}
-		if (collide(player_x, player_y, level,
-		            'z')) // Collide with nbswitch block
-		{
-			for (int i = 0; level[i] != '\0'; i++) {
-				if (level[i] == 'z') {
-					level[i] = '0';
-				}
-			}
+		// Collide with nbswitch block
+		if (collide(player_x, player_y, level, 'z')) {
+			replace_all_block('z', '0', level);
 			check_nbswitch = 1;
 		}
-		if (level[((player_x + 6) / 16) + ((player_y + 6) / 16) * 25] ==
-		    'l') // Collide with change block
-		{
+		// Collide with change block
+		if (collide_center(player_x, player_y, level, 'l')) {
 			int x = 0;
 			int y = 0;
 			char level2[351] = {0};
 			int j = 0;
-			level[((player_x + 6) / 16) +
-			      ((player_y + 6) / 16) * 25] = 'P';
+			replace_xy_block(player_x + 6, player_y + 6, 'P',
+			                 level);
 			for (int i = 349; i != -1; i--) {
 				level2[j] = level[i];
 				j++;
@@ -326,38 +321,39 @@ void game(int *id_level, char mode, char *type)
 					level[i] = '0';
 					break;
 				}
-				x += 16;
-				if (x == 16 * 25) {
+				x += TILE_HEIGHT;
+				if (x == TILE_HEIGHT * LEVEL_WIDTH) {
 					x = 0;
-					y += 16;
+					y += TILE_HEIGHT;
 				}
 				i++;
 			}
-			if (!gravity)
+			if (gravity == -1)
 				gravity = 1;
 			else
-				gravity = 0;
+				gravity = -1;
 			chock++;
 		}
 
+		// Damaged block
 		if (collide(player_x, player_y + (int)vspd + 2, level, 'B') &&
-		    vspd >= 5) // Damaged block
-		{
+		    vspd >= 5) {
 			if (level[((player_x) / 16) +
 			          ((player_y + 25) / 16) * 25] == 'B')
-				level[((player_x) / 16) +
-				      ((player_y + 25) / 16) * 25] = '0';
+				replace_xy_block(player_x, player_y + 25, '0',
+				                 level);
+
 			if (level[((player_x + 12) / 16) +
 			          ((player_y + 25) / 16) * 25] == 'B' &&
 			    collide_point(player_x + 12, player_y + 22, level,
 			                  'B'))
-				level[((player_x + 12) / 16) +
-				      ((player_y + 25) / 16) * 25] = '0';
+				replace_xy_block(player_x + 12, player_y + 25,
+				                 '0', level);
 			vspd = 1.0;
 		}
+		// Damaged block
 		if (collide(player_x, player_y - (int)vspd - 2, level, 'B') &&
-		    vspd >= 5) // Damaged block
-		{
+		    vspd >= 5) {
 			if (level[((player_x) / 16) +
 			          ((player_y - (int)vspd - 2) / 16) * 25] ==
 			    'B')
@@ -375,58 +371,46 @@ void game(int *id_level, char mode, char *type)
 			vspd = 1.0;
 		}
 
-		collide_replace(player_x, player_y, level, 'h',
-		                'y'); // Appear block
-		if (!collide(player_x, player_y, level, 'y') &&
-		    double_check) // Appear block
-		{
+		// Appear block
+		collide_replace(player_x, player_y, level, 'h', 'y');
+		// Appear block
+		if (!collide(player_x, player_y, level, 'y') && double_check) {
 			for (int i = 0; level[i] != '\0'; i++) {
-				if (level[i] == 'y') {
-					double_check = 1;
-					break;
-				} else if (level[i] == 'h') {
+				if (level[i] == 'y' || level[i] == 'h') {
 					double_check = 1;
 					break;
 				} else
-					double_check =
-					    0; // This loop is executed only
-					       // when an h or y is on the level
-			}
-			for (int i = 0; level[i] != '\0'; ++i) {
-				if (level[i] == 'y') {
-					level[i] = 'H';
-				}
+					double_check = 0;
 			}
+			replace_all_block('y', 'H', level);
 		}
-		if (level[((player_x + 6) / 16) + ((player_y + 6) / 16) * 25] ==
-		    'S') // Switch block
-		{
-			level[((player_x + 6) / 16) +
-			      ((player_y + 6) / 16) * 25] = '0';
+
+		// Switch block
+		if (collide_center(player_x, player_y, level, 'S')) {
+			replace_xy_block(player_x + 6, player_y + 6, '0',
+			                 level);
 			vspd = 1.0;
-			if (!gravity)
+			if (gravity == -1)
 				gravity = 1;
 			else
-				gravity = 0;
+				gravity = -1;
 		}
 
-		if ((framelevel / FPS) > disappear)
-			for (int i = 0; level[i] != '\0'; i++)
-				if (level[i] == 'c')
-					level[i] = '0'; // after x seconds
-					                // blocks disappear
-		if ((framelevel / FPS) > appear)
-			for (int i = 0; level[i] != '\0'; i++)
-				if (level[i] == 'm')
-					level[i] = 'C'; // after x seconds
-					                // blocks appear
+		if ((framelevel / FPS) > disappear - 1) {
+			replace_all_block('c', '0', level);
+		}
+		if ((framelevel / FPS) > appear - 1) {
+			replace_all_block('m', 'C', level);
+		}
 
+		// warp
 		if (player_y >= 212)
 			player_y = -4;
 		if (player_y < -6)
 			player_y = 212;
 
 		// Menu
+
 		if (keydown_any(KEY_EXIT, KEY_MENU, 0)) {
 			char menu_loop = 1;
 			char selected = 0;
@@ -451,7 +435,7 @@ void game(int *id_level, char mode, char *type)
 					      "SPEEDRUN MENU");
 				dtext(16, Y_POS + (selected * 12), C_BLACK,
 				      ">");
-				dprint(180, 45, C_RGB(83, 255, 0), "LEVEL : %d",
+				dprint(180, 45, C_BLACK, "LEVEL : %d",
 				       *id_level);
 				dprint(320, 3, C_RGB(255, 178, 0), "COIN : %d",
 				       coin);
@@ -487,12 +471,10 @@ void game(int *id_level, char mode, char *type)
 	if (mode) {
 		if (*id_level == 0) {
 			game_loop = 0;
-			draw_end(framelevel, *id_level, 0);
-			sleep_ms(2500);
 			*id_level = 1;
 		}
-		if (game_loop) // end of a level with level selection
-		{
+		// end of a level with level selection
+		if (game_loop) {
 			float framefloat = framelevel;
 			draw_end(framelevel, *id_level, 0);
 			savetime(framefloat, *id_level);
@@ -507,42 +489,3 @@ void game(int *id_level, char mode, char *type)
 	} else
 		main();
 }
-
-void end(unsigned int frame)
-{
-	draw_end((int)frame, 15, 2);
-	sleep_ms(7000);
-	main();
-}
-
-int main(void)
-{
-	if (!run) {
-		gint_world_switch(GINT_CALL(restore));
-		run = 1;
-	}
-	char mode = 0;
-	char type = 1;
-	char valeur = start_menu(&type);
-	if (!valeur) // normal game (level selection)
-	{
-		int id_level = 1;
-		if (!speed_menu(&id_level)) {
-			mode = 1;
-			game(&id_level, mode, &type);
-		} else
-			main();
-	} else if (valeur == 1) // all mode
-	{
-		int id_level = 1;
-		mode = 0;
-		game(&id_level, mode, &type);
-	} else if (valeur == 2) // tutorial
-	{
-		int id_level = 0;
-		mode = 1;
-		game(&id_level, mode, &type);
-	} else if (valeur == 3) // exit
-		gint_world_switch(GINT_CALL(savefile));
-	return 0;
-}
diff --git a/src/menu.c b/src/menu.c
index 6f7e0a6..f9f60e0 100644
--- a/src/menu.c
+++ b/src/menu.c
@@ -1,18 +1,15 @@
+#include "menu.h"
 #include "define.h"
 #include "drawlevel.h"
 #include "save.h"
 #include "setlevel.h"
 #include "times.h"
+#include "util.h"
 #include <gint/display.h>
 #include <gint/gint.h>
 #include <gint/keyboard.h>
 
-int round(float num) // round(2.5) = 3 round(-3.2) = -3
-{
-	return num < 0 ? num - 0.5 : num + 0.5;
-}
-
-char start_menu(char *type)
+enum MenuCode start_menu(char *type)
 {
 	extern bopti_image_t img_menu;
 	char menu_loop = 1;
@@ -56,7 +53,7 @@ char start_menu(char *type)
 char speed_menu(int *id_level)
 {
 	char level[351];
-	char gravity = 0; // 0 down 1 up
+	char gravity = -1; // -1 down 1 up
 	int start_x;
 	int start_y;
 	char buffer = 1;
@@ -87,6 +84,7 @@ char speed_menu(int *id_level)
 		dtext(340, 214, C_BLACK, "TIMES");
 		dtext(190, 45, C_BLACK, "Time : ");
 		dprint(80, 20, C_BLACK, "Level : %d", *id_level);
+		dprint(80, 50, C_RED, "%d", gravity);
 		if (sto != 0)
 			dprint(194, 60, C_RED, "%.2j", sto);
 		else
diff --git a/src/replace.c b/src/replace.c
new file mode 100644
index 0000000..f6d2ac4
--- /dev/null
+++ b/src/replace.c
@@ -0,0 +1,16 @@
+#include "replace.h"
+#include "define.h"
+#include <gint/keyboard.h>
+
+void replace_all_block(char a, char b, char level[])
+{
+	for (int i = 0; i < LEVEL_WIDTH * LEVEL_HEIGHT; i++) {
+		if (level[i] == a)
+			level[i] = b;
+	}
+}
+
+void replace_xy_block(int x, int y, char block, char level[])
+{
+	level[(x / TILE_HEIGHT) + ((y / TILE_HEIGHT) * LEVEL_WIDTH)] = block;
+}
\ No newline at end of file
diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..b5ca196
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,3 @@
+#include "util.h"
+
+int round(float num) { return (num < 0) ? (num - 0.5) : (num + 0.5); }
diff --git a/times.lvl b/times.lvl
index 285c365..87ac474 100755
--- a/times.lvl
+++ b/times.lvl
@@ -15,3 +15,4 @@
 7.45
 10.53
 17.95
+9.54
diff --git a/update_levels.sh b/update_levels.sh
index 6688bb4..223650e 100755
--- a/update_levels.sh
+++ b/update_levels.sh
@@ -1,5 +1,8 @@
 #!/bin/sh
 echo "#define LEVEL_MAX $(ls editor/levels/[^0]*.lvl | wc -l)
 #define PLAYER_HEIGHT 11
-#define FPS 70" > generated/include/define.h
+#define FPS 70
+#define LEVEL_WIDTH 25
+#define LEVEL_HEIGHT 14
+#define TILE_HEIGHT 16" > generated/include/define.h
 python3 compile_levels.py