Update Snake: wrap edges and halve speed

snake.lua:
- Changed wall collision to wrap around (toroidal grid)
- Snake now travels through edges instead of crashing
- Doubled move_speed from 10 to 20 frames (half speed)
- Updated speed increase cap from 3 to 5 frames (slower at max)
- Snake can now traverse indefinitely without losing to walls

games/lua_examples/snake.lua

@@ -30,7 +30,7 @@ function init()
     game.vars.food_y = 14
     
     game.vars.frame_count = 0
-    game.vars.move_speed = 10  -- Frames between moves
+    game.vars.move_speed = 20  -- Frames between moves (doubled from 10 for half speed)
     
     -- Enable continuous frame updates
     game.set_frame_updates(true)
@@ -167,15 +167,13 @@ end
 function move_snake()
     local head = game.vars.snake[1]
     local new_head = {
-        x = head.x + game.vars.dir_x,
-        y = head.y + game.vars.dir_y
+        x = (head.x + game.vars.dir_x) % GRID_W,
+        y = (head.y + game.vars.dir_y) % GRID_H
     }
     
-    -- Check wall collision
-    if new_head.x < 0 or new_head.x >= GRID_W or new_head.y < 0 or new_head.y >= GRID_H then
-        game_over()
-        return
-    end
+    -- Wrap around negative values (Lua modulo behavior)
+    if new_head.x < 0 then new_head.x = new_head.x + GRID_W end
+    if new_head.y < 0 then new_head.y = new_head.y + GRID_H end
     
     -- Check self collision
     for i = 1, #game.vars.snake do
@@ -193,8 +191,8 @@ function move_snake()
         game.vars.score = game.vars.score + 10
         spawn_food()
         
-        -- Increase speed slightly
-        if game.vars.move_speed > 3 then
+        -- Increase speed slightly (but keep it slower overall)
+        if game.vars.move_speed > 5 then
             game.vars.move_speed = game.vars.move_speed - 1
         end
     end