diff --git a/examples/game-tetris.ds b/examples/game-tetris.ds
index f3ef41d..2c861bc 100644
--- a/examples/game-tetris.ds
+++ b/examples/game-tetris.ds
@@ -85,16 +85,13 @@ on keydown(ev) -> paused = if ev.key == "p" then (if paused then 0 else 1) else
 -- ================================================================
 
 -- Collision detection: can the piece move down?
--- T-piece at py: top row at py (3 cells), bottom cell at py+1 (1 cell).
--- Moving down: top row -> py+1, bottom cell -> py+2.
--- Must check BOTH:
---   grid[py+1] at px, px+1, px+2  (top row destination)
---   grid[py+2] at px+1            (bottom cell destination)
+-- All pieces: check grid[py+1] at px, px+1, px+2 (top row destination).
+-- T-piece (6) only: also check grid[py+2] at px+1 (protruding bottom cell).
 -- Bottom wall: py >= 18.
 let blocked = 0
 
--- Full collision: top row (grid[py+1]) + bottom cell (grid[py+2])
-every 33 -> blocked = if py > 17 then 1 else (if py == 17 then (if g18[px] > 0 then 1 else (if g18[px + 1] > 0 then 1 else (if g18[px + 2] > 0 then 1 else (if g19[px + 1] > 0 then 1 else 0)))) else (if py == 16 then (if g17[px] > 0 then 1 else (if g17[px + 1] > 0 then 1 else (if g17[px + 2] > 0 then 1 else (if g18[px + 1] > 0 then 1 else 0)))) else (if py == 15 then (if g16[px] > 0 then 1 else (if g16[px + 1] > 0 then 1 else (if g16[px + 2] > 0 then 1 else (if g17[px + 1] > 0 then 1 else 0)))) else (if py == 14 then (if g15[px] > 0 then 1 else (if g15[px + 1] > 0 then 1 else (if g15[px + 2] > 0 then 1 else (if g16[px + 1] > 0 then 1 else 0)))) else (if py == 13 then (if g14[px] > 0 then 1 else (if g14[px + 1] > 0 then 1 else (if g14[px + 2] > 0 then 1 else (if g15[px + 1] > 0 then 1 else 0)))) else (if py == 12 then (if g13[px] > 0 then 1 else (if g13[px + 1] > 0 then 1 else (if g13[px + 2] > 0 then 1 else (if g14[px + 1] > 0 then 1 else 0)))) else 0))))))
+-- Piece-aware collision: top row for all, bottom cell only for T-piece
+every 33 -> blocked = if py > 17 then 1 else (if py == 17 then (if g18[px] > 0 then 1 else (if g18[px + 1] > 0 then 1 else (if g18[px + 2] > 0 then 1 else (if piece == 6 then (if g19[px + 1] > 0 then 1 else 0) else 0)))) else (if py == 16 then (if g17[px] > 0 then 1 else (if g17[px + 1] > 0 then 1 else (if g17[px + 2] > 0 then 1 else (if piece == 6 then (if g18[px + 1] > 0 then 1 else 0) else 0)))) else (if py == 15 then (if g16[px] > 0 then 1 else (if g16[px + 1] > 0 then 1 else (if g16[px + 2] > 0 then 1 else (if piece == 6 then (if g17[px + 1] > 0 then 1 else 0) else 0)))) else (if py == 14 then (if g15[px] > 0 then 1 else (if g15[px + 1] > 0 then 1 else (if g15[px + 2] > 0 then 1 else (if piece == 6 then (if g16[px + 1] > 0 then 1 else 0) else 0)))) else (if py == 13 then (if g14[px] > 0 then 1 else (if g14[px + 1] > 0 then 1 else (if g14[px + 2] > 0 then 1 else (if piece == 6 then (if g15[px + 1] > 0 then 1 else 0) else 0)))) else (if py == 12 then (if g13[px] > 0 then 1 else (if g13[px + 1] > 0 then 1 else (if g13[px + 2] > 0 then 1 else (if piece == 6 then (if g14[px + 1] > 0 then 1 else 0) else 0)))) else 0))))))
 
 -- Gravity tick
 every 33 -> gravityTick = if paused then gravityTick else (if gameOver then gravityTick else gravityTick + 1)