Arrow Game

Linux-native arrow-shading puzzle game that runs in Chrome OS Linux (Crostini) and other Linux desktops.

How to play

1. Sign in with a display name, Guest, or Google (Chrome account) if OAuth is configured.
2. Pick a level (Beginner → Expert). A puzzle is generated automatically.
3. The board shows a recognizable shape (apple, tree, house, heart, geometry, …) filled with arrow lines that point toward the nearest side (head only on the outer tip).
4. Hover an arrow to highlight it, then click. If its path out is clear, it slides out in green and shades cells as it goes (10 × length points). If blocked, it blinks red and plays an error sound.
5. Clear blockers first to unlock deeper arrows. When every arrow is gone, you win.
6. A time bonus (up to 500 pts) rewards faster clears. Scores are saved per user/level.

Run on Chrome OS

1. Enable Linux (Beta) if needed.
2. In the Linux terminal:

cd ~/arrow-game
sudo apt update
sudo apt install -y python3-pygame
chmod +x run.sh
./run.sh

Desktop launcher + icon (Chrome OS / Linux)

cd ~/arrow-game
chmod +x install-desktop.sh
./install-desktop.sh

This installs:

• ~/.local/share/applications/arrow-game.desktop with Icon=arrow-game
• multi-size icons under ~/.local/share/icons/hicolor/*/apps/arrow-game.png
• refreshes the desktop/icon caches

The icon is a gold arrow in a rounded box (assets/arrow-game-icon.png). It is used by the launcher and the running window / shelf (via pygame set_icon and StartupWMClass=arrow-game).

If Chrome OS still shows the default penguin after install, restart the Linux container once (crosh → vmc stop termina or reboot) so garcon re-reads icons.

Then open Arrow Game from the Chrome OS launcher (Linux apps).

Google / Chrome account login

Scores always work with a local name or Guest. For Google sign-in:

1. Create an OAuth 2.0 Desktop client in Google Cloud Console.
2. Enable the userinfo scopes (OpenID email/profile).
3. Export credentials before launch:

export ARROW_GAME_GOOGLE_CLIENT_ID="….apps.googleusercontent.com"
export ARROW_GAME_GOOGLE_CLIENT_SECRET="…"
./run.sh

The app opens Chrome on a loopback redirect (http://127.0.0.1:8765/callback). Your profile is stored in ~/.local/share/arrow-game/.

Project layout

arrow-game/
  main.py                 # entry
  run.sh                  # launcher
  arrow-game.desktop      # Chrome OS / desktop menu
  assets/
    arrow-game-icon.png   # app icon (arrow in a box)
  arrow_game/
    app.py                # UI screens & game loop
    puzzle.py             # generation + play rules
    levels.py             # difficulty presets
    auth.py               # Google OAuth + guest/local
    storage.py            # scores & profile JSON
    ui.py / config.py
  data/                   # optional runtime data

Puzzle generation

Puzzles are solvable by construction:

1. Stamp a template silhouette (object or geometric form) onto the level grid.
2. Fill free cells with winding arrows: random segment length (capped by segment_size), then a turn, repeat until the path hits the edge of the free region (endpoint). Paths never self-overlap.
3. Carve in solution order so each arrow can exit when placed; reverse order is a valid solve. Generation retries until move count is in the level band.

Level knobs

Higher difficulty uses smaller cells inside a fixed play area (720×540 px every level). Grid dimensions are derived from the cell size so each level fills that area exactly (e.g. 45px → 16×12, 15px → 48×36). Glyph line weight and heads scale from a design BASE_CELL. Paths are biased long and bendy.

Level	Cell	Grid	Moves (solve)	Max segment (cells)
Beginner	45px	16×12	3–7	10
Easy	36px	20×15	6–12	12
Medium	30px	24×18	10–18	14
Hard	20px	36×27	16–28	16
Expert	15px	48×36	22–40	18

Holes in silhouettes (e.g. Ring) are filled with playable purple arrows. They follow the same exit rules: blocked until the path out is clear, and they block other arrows whose exit ray crosses them.

Calibrate with: PYTHONPATH=. python3 -m arrow_game.analyze_levels

Scoring

Event	Points
Remove arrow of length L	L × 10
Click a blocked arrow	−10
Time under target	5 per whole second under target
Target time	5 × number of arrows (seconds)

Data files: ~/.local/share/arrow-game/profile.json, scores.json.

Headless self-test

python3 -c "from arrow_game.puzzle import generate_puzzle, verify_solvable; from arrow_game.levels import LEVELS
for lv in LEVELS:
  p=generate_puzzle(lv, seed=42)
  assert verify_solvable(p), lv.name
  print(lv.name, 'ok', len(p.arrows), 'arrows', len(p.shape), 'cells')"