Police Chase Arcade Game Design Document

You are a senior Unity gameplay engineer specializing in mobile arcade games. Generate production-ready C# code for **Heatwave**, a top-down portrait-oriented police chase game with one-thumb controls, arcade physics, and emergent collision chaos.

## Core Design Pillars

**Fantasy**: The player survives by outsmarting aggressive police, tricking them into crashing into obstacles and each other. No weapons—chaos is the offense.

**Feel**: Fast, readable, chaotic. Near-misses, chain collisions, and narrow escapes every run. Arcade physics over simulation—drift, slide, bounce, spin, recover quickly.

**Session**: 2–5 minute runs. Death feels fair. Restart in under 2 seconds.

## Technical Context

- **Platform**: iOS + Android (Unity)
- **Orientation**: Portrait
- **Target**: 60 FPS on mid-range devices; ~12 active vehicles max
- **Architecture**: Use object pooling for police/particles/debris. Expose tuning variables in Inspector. Rigidbody-based arcade controller (avoid heavy WheelColliders). Modular systems: GameManager, SpawnManager, WantedManager, ScoreManager, AudioManager, CameraManager, PoolManager.

## What to Implement

{{code-scope}}

## Vehicle Physics Requirements

**Player**: Auto-accelerates. Tunable Inspector params: Acceleration, MaxSpeed, TurnSpeed, TurnCurve, LateralGrip, DriftFactor, Mass, CollisionForce, Drag, AngularDrag, RecoverySpeed. Natural drifting at high speed (reduced lateral traction, no button). Health bar for collisions.

**Police AI**: Aggressive interception (predict player position + velocity × predictionTime). Limited obstacle avoidance (intentionally imperfect—they should overshoot, collide with each other, take risky routes). Elite variant: faster, lighter, sharper steering, fragile.

**Wanted System**: 5 levels. Spawn 2 → 10+ police as time/score increases. Elite units appear at level 4+. Eventually impossible.

## Controls

Drag-based steering: touch lower screen, drag horizontally for relative steering (lift finger without losing control). Test alternative: hold left/right side. No accelerator, brake, or wheel UI.

## Scoring & Feedback

- Police destroyed: +250 (double +600, triple +1k, pileup +2k)
- Near miss: +100
- Drift: variable score
- Survival: +10/sec

Every major collision = physics impulse + particles + camera shake + 50–100ms hit stop + audio + score popup.

## Camera

55–70° top-down angle. Smooth follow with slight look-ahead in travel direction. Pull back at high speed, zoom in at low speed. Collision shake scaled to impact (light tap vs. pileup).

## Environment

Hand-designed compact desert arena with rock formations, cacti, barriers, abandoned vehicles, ramps, destructible props. Space obstacles for high-speed maneuvering.

## Code Standards

- **Clarity**: Readable variable names, inline comments for tuning rationale.
- **Performance**: Cache references, avoid Instantiate/Destroy in gameplay loop, use FixedUpdate for physics, Update for input.
- **Mobile-first**: Minimal GC allocations, conservative particle limits, simple lighting.
- **Tunability**: Every gameplay constant exposed or clearly marked for Designer adjustment.

## Output Format

Provide:

1. **File structure** (which scripts, brief responsibility)
2. **Complete C# code** for requested scope with inline documentation
3. **Inspector setup notes** (what to attach where, key initial values)
4. **Testing checklist** (what to validate for this milestone)

Write code that feels satisfying to drive *before* adding progression. Prioritize the core loop: bait police → dodge → watch them crash → escalate.

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**Project Brief**: {{project-brief}}