diff --git a/assets/tiles/demo_tilemap.tilemap.json b/assets/tiles/demo_tilemap.tilemap.json
new file mode 100644
index 0000000..bd6c2ca
--- /dev/null
+++ b/assets/tiles/demo_tilemap.tilemap.json
@@ -0,0 +1,8 @@
+{
+  "id": "demo_tilemap",
+  "tile_size": 32,
+  "tiles": [
+    {"id": "grass", "walkable": true},
+    {"id": "stone", "walkable": false}
+  ]
+}
diff --git a/init.lua b/init.lua
index 8c6341c..403fe31 100644
--- a/init.lua
+++ b/init.lua
@@ -8,11 +8,15 @@ local player_control  = { hello = function() return "player_control stub" end }
 local actor           = { hello = function() return "actor stub" end }
 local interaction     = { hello = function() return "interaction stub" end }
 
+-- Load + activate the demo map (P.0.lib.maps slice)
+local demo_map = maps.load("maps/demo.map.json")
+maps.set_current(demo_map)
+
 local frames = 0
 local TARGET_FRAMES = 60
 
 function init(ctx)
-    engine.print("spine-prototype init: " .. maps.hello())
+    engine.print("spine-prototype init: maps loaded")
     engine.print("inline stubs loaded: "
         .. render.hello() .. ", "
         .. camera.hello() .. ", "
@@ -20,6 +24,16 @@ function init(ctx)
         .. player_control.hello() .. ", "
         .. actor.hello() .. ", "
         .. interaction.hello())
+
+    local size = maps.size()
+    engine.print(string.format("map size: %dx%d", size.w, size.h))
+
+    local corner = maps.tile_at(0, 0)
+    local interior = maps.tile_at(5, 5)
+    engine.print("tile at (0,0): " .. corner.id)
+    engine.print("tile at (5,5): " .. interior.id)
+    engine.print("walkable at (0,0): " .. tostring(maps.is_walkable(0, 0)))
+    engine.print("walkable at (5,5): " .. tostring(maps.is_walkable(5, 5)))
 end
 
 function update(ctx, dt)
diff --git a/maps/demo.map.json b/maps/demo.map.json
new file mode 100644
index 0000000..af8d150
--- /dev/null
+++ b/maps/demo.map.json
@@ -0,0 +1,23 @@
+{
+  "id": "demo",
+  "tilemap": "demo_tilemap",
+  "size": {"w": 16, "h": 16},
+  "tiles": [
+    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,
+    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2
+  ]
+}