diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..091f4ab
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,6 @@
+[submodule "assets-cg"]
+	path = assets-cg
+	url = https://gitea.planet-casio.com/KikooDX/jtmm2-assets-cg
+[submodule "assets-fx"]
+	path = assets-fx
+	url = https://gitea.planet-casio.com/KikooDX/jtmm2-assets-fx
diff --git a/assets-cg b/assets-cg
new file mode 160000
index 0000000..09b5adf
--- /dev/null
+++ b/assets-cg
@@ -0,0 +1 @@
+Subproject commit 09b5adf91b66e0a35096fcbfd6885938afa118d8
diff --git a/assets-cg/icon-cg-sel.png b/assets-cg/icon-cg-sel.png
deleted file mode 100644
index ecf3f76..0000000
Binary files a/assets-cg/icon-cg-sel.png and /dev/null differ
diff --git a/assets-cg/icon-cg-uns.png b/assets-cg/icon-cg-uns.png
deleted file mode 100644
index a024737..0000000
Binary files a/assets-cg/icon-cg-uns.png and /dev/null differ
diff --git a/assets-fx b/assets-fx
new file mode 160000
index 0000000..58c1314
--- /dev/null
+++ b/assets-fx
@@ -0,0 +1 @@
+Subproject commit 58c131401c021ac3aaabc23b7387f9143769072c
diff --git a/assets-fx/icon-fx.png b/assets-fx/icon-fx.png
deleted file mode 100644
index b759374..0000000
Binary files a/assets-fx/icon-fx.png and /dev/null differ
diff --git a/include/tiles.h b/include/tiles.h
index f3270c9..4c16dc3 100644
--- a/include/tiles.h
+++ b/include/tiles.h
@@ -1,20 +1,37 @@
 #ifndef _DEF_TILES
 #define _DEF_TILES
+#define TILE_AT(x, y) (x + y * 8)
+
 typedef unsigned char Tile; /* the tile ID */
 typedef unsigned char Tile_flags; /* the tile properties (bitmask) */
 
 /* define flags */
-#define F_VISIBLE 0b1
-#define F_SOLID 0b10
+#define F_SOLID 0b1
+#define F_SLIPPERY 0b10
 
 /* define properties */
 #define P_AIR		(0)
-#define P_BASE		(F_VISIBLE | F_SOLID)
-#define P_UNKNOWN	(F_VISIBLE)
+#define P_BASE		(F_SOLID)
+#define P_UNKNOWN	(0)
 
 enum {
-	ID_AIR,
-	ID_BASE,
+	ID_AIR		= TILE_AT(0, 0),
+	ID_BASE_0	= TILE_AT(1, 0),
+	ID_BASE_1	= TILE_AT(2, 0),
+	ID_BASE_2	= TILE_AT(3, 0),
+	ID_BASE_3	= TILE_AT(4, 0),
+	ID_BASE_4	= TILE_AT(1, 1),
+	ID_BASE_5	= TILE_AT(2, 1),
+	ID_BASE_6	= TILE_AT(3, 1),
+	ID_BASE_7	= TILE_AT(4, 1),
+	ID_BASE_8	= TILE_AT(1, 2),
+	ID_BASE_9	= TILE_AT(2, 2),
+	ID_BASE_10	= TILE_AT(3, 2),
+	ID_BASE_11	= TILE_AT(4, 2),
+	ID_BASE_12	= TILE_AT(1, 3),
+	ID_BASE_13	= TILE_AT(2, 3),
+	ID_BASE_14	= TILE_AT(3, 3),
+	ID_BASE_15	= TILE_AT(4, 3),
 };
 
 Tile_flags tile_get_flags(Tile tile);
diff --git a/levels/create_demo.lua b/levels/create_demo.lua
index 899203e..adc7953 100755
--- a/levels/create_demo.lua
+++ b/levels/create_demo.lua
@@ -6,7 +6,7 @@ local function create_random_level(width, height, layers)
   io.write(height, "\n")
   for i = 1, layers, 1 do
     for r = 1, width * height, 1 do
-     io.write(math.floor(math.random() * 1.5)) --random 0 (2/3) or 1 (1/3)
+      io.write(math.ceil(math.random() * 4) * math.floor(math.random() * 1.5))
       io.write("\n")
     end
     if i ~= layers then
diff --git a/src/level.c b/src/level.c
index be57457..f1e2eac 100644
--- a/src/level.c
+++ b/src/level.c
@@ -17,6 +17,8 @@ void level_draw(const Level *level, Camera *camera) {
 }
 
 void layer_draw(const Level *level, Camera *camera, uint layer_id) {
+	/* Include tileset. */
+	extern bopti_image_t img_tileset;
 	const Tile *layer = level->layers[layer_id];
 	#ifdef FX9860G
 	const int color = C_LIGHT;
@@ -39,10 +41,12 @@ void layer_draw(const Level *level, Camera *camera, uint layer_id) {
 		for (int x = start_x; x < end_x; ++x) {
 			const Tile tile = layer[x + y * level->width];
 			if (tile) {
-				Vec tl = {
+				const Vec tl = {
 					(x * TILE_SIZE / VEC_PRECISION - camera->offset.x) * SCALE,
 					(y * TILE_SIZE / VEC_PRECISION - camera->offset.y) * SCALE };
-				drect(tl.x, tl.y, tl.x + TILE_PX_SIZE, tl.y + TILE_PX_SIZE, color);
+				dsubimage(tl.x, tl.y, &img_tileset,
+					tile * TILE_PX_SIZE, 0 * TILE_PX_SIZE,
+					TILE_PX_SIZE, TILE_PX_SIZE, 0);
 			}
 		}
 	}
diff --git a/src/tiles.c b/src/tiles.c
index 5a83f28..3972957 100644
--- a/src/tiles.c
+++ b/src/tiles.c
@@ -3,7 +3,24 @@
 Tile_flags tile_get_flags(Tile tile) {
 	switch (tile) {
 		case ID_AIR: return P_AIR; break;
-		case ID_BASE: return P_BASE; break;
+		case ID_BASE_0:
+		case ID_BASE_1:
+		case ID_BASE_2:
+		case ID_BASE_3:
+		case ID_BASE_4:
+		case ID_BASE_5:
+		case ID_BASE_6:
+		case ID_BASE_7:
+		case ID_BASE_8:
+		case ID_BASE_9:
+		case ID_BASE_10:
+		case ID_BASE_11:
+		case ID_BASE_12:
+		case ID_BASE_13:
+		case ID_BASE_14:
+		case ID_BASE_15:
+			return P_BASE;
+			break;
 		default: return P_UNKNOWN; break;
 	}
 }