Neon Runner

A browser-based arcade game built with Excalibur.js. Jump over obstacles, survive as long as possible, and chase a high score as the neon cityscape accelerates around you.

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Gameplay

• Jump over incoming obstacles using Space or ↑
• Speed increases every 3 seconds — survive as long as you can
• Score accumulates over time; every 100 points triggers an audio cue
• Hit an obstacle → screen shake, game over, restart with Space or Enter

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What's New

Performance optimizations:

• Eliminated per-frame allocations in parallax and obstacle systems
• GPU-accelerated CSS overlay layers
• Cached AudioContext.currentTime in sound methods
• Guarded score label updates to skip unnecessary redraws
• Optimized camera shake reset (single call instead of per-frame check)

Bug fixes:

• AudioContext now resumes on first interaction (fixes silent audio in Chrome)
• Obstacle gaps scale with speed so obstacles stay clearable at max difficulty
• Game freezes player and obstacles during death shake (no ghost movement)
• Scene transition syncs with shake completion for clean handoff
• Time-based input cooldown on restart prevents ghost jumps
• Score passes correctly from GameScene to GameOverScene
• Replaced setTimeout with engine-time timer to prevent drift

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Tech Stack

Tool	Role
Excalibur.js v0.32	2D game engine (actors, physics, scenes, input)
TypeScript 5.9	Type-safe game logic
Vite 8	Dev server + production build
Vitest 4	Unit tests
Web Audio API	Synthesized sound effects (no audio assets)

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Getting Started

npm install
npm run dev

Open http://localhost:5173 in your browser.

Other Commands

npm run build    # production build → dist/
npm run preview  # serve the production build locally
npm test         # run unit tests

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Project Structure

src/
├── main.ts                    # Engine init, scene registration
├── config.ts                  # All game constants (speeds, colors, physics)
├── actors/
│   ├── Player.ts              # Jump mechanics, ground detection, input cooldown
│   ├── Obstacle.ts            # Randomly-sized obstacles
│   ├── Ground.ts              # Static collision platform
│   └── ParallaxBackground.ts  # 3-layer depth scrolling
├── scenes/
│   ├── GameScene.ts           # Main loop: score, speed scaling, collision
│   └── GameOverScene.ts       # End screen + restart listener
├── systems/
│   └── ObstacleSpawner.ts     # Procedural spawning with random gaps
└── audio/
    └── SoundManager.ts        # Synthesized jump / game-over / score sounds

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Configuration

All tunable constants live in src/config.ts:

Constant	Default	Description
initialSpeed	300 px/s	Starting scroll speed
maxSpeed	800 px/s	Speed cap
speedIncrement	+20	Added every 3 seconds
jumpForce	-700	Upward velocity on jump
gravity	1800	Downward acceleration
minObstacleGap	300 px	Minimum gap between obstacles
maxObstacleGap	600 px	Maximum gap between obstacles

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License

MIT