DBL-SYSTEMS
Single prompt

Snake Game

Single-prompt output. Play it here; prompt and run record below.

Numbers

Status
Playable run 01
Format
Single HTML file
Engine
Canvas, ES6+
Runs
1 recorded
Outputs
1 playable
File size
22,769 bytes
Grid
24 x 24
Tick
115 ms
Controls
Keyboard, touch, swipe
Play data
Pending manual sessions
Build Instruction Prompt published 
Build a polished Snake game as a single self-contained HTML file.

Requirements:
- One HTML file only
- No external dependencies
- No frameworks
- No CDN assets
- Inline CSS and JavaScript only
- Runs directly in browser
- Keyboard controls
- Smooth and deterministic game loop
- Food spawning
- Snake growth
- Collision detection
- Wall death
- Self-collision death
- Score tracking
- Restart support
- Mobile-friendly layout
- Clean retro arcade visual style

Technical constraints:
- Use HTML5 Canvas
- Use ES6+ JavaScript
- Keep all game state centralized
- Separate rendering, input, update, and collision logic clearly
- Use delta-time or fixed-timestep logic to avoid framerate issues
- Avoid unnecessary abstractions
- Prefer stability and readability over clever code

Before coding:
1. Briefly describe architecture
2. Identify likely failure points
3. Define mitigation strategy

Failure points to consider:
- Input buffering causing instant self-collision
- Snake overlap bugs
- Food spawning inside snake body
- Timing inconsistency at different FPS
- Restart state corruption

After implementation:
- Perform a short self-review
- Verify no placeholder logic exists
- Verify no missing functions exist
- Verify the game is fully playable
- Verify no external libraries or assets are used
Model Runs 1 recorded
run-01 Playable

GPT-5.5 xhigh fast

Implemented as a standalone HTML5 Canvas Snake game with centralized state, fixed-timestep movement, keyboard controls, touch controls, swipe input, restart support, and local best-score storage.

Family
OpenAI GPT-5.5
Date
2026-05-21
Duration
Single Codex implementation turn
Environment
Codex desktop, Astro static public repo

Strengths

  • Single self-contained HTML file with no external imports.
  • Input queue blocks immediate reverse direction and instant self-collision.
  • Food spawning samples only cells outside the snake body.
  • Self-collision checks exclude the moving tail unless the snake is growing.
  • Restart creates a fresh state and clears accumulator timing.

Weaknesses

  • No screenshot capture recorded yet.
  • No automated browser gameplay trace recorded yet.
Output Comparison 1 outputs
output-01 Playable

GPT-5.5 xhigh fast HTML

Standalone retro arcade Snake surface. Runs directly in the browser and can be embedded into the lab record.

Open output
Trait Target Current
Works out of the box Yes Yes, local route returns 200
Visual polish Clean retro arcade Dark arcade cockpit, grid board, compact HUD
Code cleanliness Readable ES6+ Central state with separated input, update, collision, and render logic
File size Single compact HTML 22,769 bytes
Responsiveness Mobile-friendly Responsive layout, touch pad, and swipe support
Restart support Required Start, Restart, and Enter reset paths
Determinism Fixed timestep 115ms fixed update step with capped frame delta
External dependencies None None detected
Implementation Notes 4 notes
  • Architecture: one centralized state object drives input, fixed-timestep update, collision handling, rendering, and HUD synchronization.
  • Failure mitigation: reverse input is rejected against both current and queued direction; food only spawns in free cells; self-collision excludes the moving tail unless growing.
  • Restart mitigation: resetGame rebuilds the snake, direction, score, food, flags, accumulator, and timing baseline.
  • Self-review: no external libraries or assets were used; the script block parses successfully; the artifact route returns 200 locally.