| name | demo-1-terminal-arcade |
| description | Demo skill that builds a colorful, playable terminal Snake game in a single pure-stdlib Python curses file — score HUD, speed ramp, eat/death animations, and a game-over screen. |
Build a playable, colorful game of Snake that runs in the terminal, as a single self-contained
Python file .decode/outputs/snake.py (unless the human named a different path).
Constraints
- Pure standard library only — use the built-in
curses module for rendering and input. Add zero
third-party dependencies (nothing that would need uv add or pip install).
- Keep it small and readable: roughly 250 lines. This is a demo people will read, not just play.
Plan first
Before writing any code, lay out your steps with todo_write (draw field → snake movement → food
and growth → color + HUD → game over → smoke checks) and tick them off as you go.
Gameplay to implement
- A bordered play field drawn with
curses.
- A snake that moves continuously and is steered with W, A, S, D (arrow keys as a fallback).
- q (or Q) and ESC quit the game at any moment.
- Food that spawns at a random empty cell; eating it grows the snake and increases the score.
- Game over when the snake hits a wall or itself; show a centered "GAME OVER — score N" screen and
wait for a keypress to exit.
- Restore the terminal cleanly on exit (use
curses.wrapper so a crash never leaves the terminal
garbled).
Make it flashy
- Color (guard with
curses.has_colors()): green snake, red food, yellow score bar, white
borders — set up curses.init_pair pairs once at start and fall back to plain text when colors
are unsupported.
- Score HUD: a top status line like
SCORE 7 · SPEED 3 that updates live.
- Speed ramp: every 3 pieces of food eaten, shorten the tick timeout a little so the game gets
faster — cap it so it stays playable.
- Eat animation: a short, non-blocking flourish when the snake eats food — e.g. flash the
snake's head or pulse the score in the HUD for a few ticks. It must not pause the game loop.
- Death animation: on game over, a brief sequence before the "GAME OVER" screen — e.g. flash
the snake a few times or make it disintegrate tail-to-head. Keep it under ~a second so quitting
never feels sluggish.
How to iterate
curses needs a real TTY, so you cannot fully play it headlessly. Iterate like this instead:
- After each change, syntax-check it:
uv run python -m py_compile .decode/outputs/snake.py.
- Factor the pure logic — food placement, collision detection, the speed-for-score curve — into
small functions and exercise them headlessly with
uv run python -c "...". Guard the
curses.wrapper(main) call behind if __name__ == "__main__": so importing the module never
grabs the terminal.
- Hand the finished
snake.py to the human to play with uv run python .decode/outputs/snake.py.
Report the final file, the controls, and the one-line command to play it.
