# Game Design Document — Fast & Furious: Tokyo Expressway (MVP)

## Vision
A progression-fantasy street racer. You start in a humble-but-iconic 1993 Mazda
RX-7 and claw your way up to hypercars on a neon-drenched Tokyo expressway at night.
Easy to pick up, satisfying to grind, fair to spend on.

## The one-sentence pitch
"Start in the RX-7, own the expressway."

## Core loop (the addictive 60 seconds)
1. **Spawn** on the expressway in your equipped car.
2. **Race** the time-trial down the highway to the finish line.
3. **Earn** cash + reputation for finishing.
4. **Spend** in the Garage: upgrade your current car or buy the next tier.
5. A faster car / better tune makes the next race feel better → back to step 1.

Daily rewards + rising rep gates give a reason to come back tomorrow.

## Pillars
- **Progression fantasy** — junker → hypercar, always a visible next goal.
- **Nighttime Tokyo vibe** — neon, speed, style.
- **Fair monetization** — spending accelerates the grind, never buys wins.
- **Server-authoritative** — no exploiting money or unlocking cars.

## MVP feature set (what's built)
- 5-tier car catalogue; **RX-7 is the free starter** (Tier 2).
- Drivable cars via VehicleSeat (proven, swap-in real mesh later).
- Procedural expressway map with kill-walls (can't leave the road).
- Garage + Dealership UI: view / buy / equip / upgrade.
- Upgrade system: Engine / Tires / Nitro, cost-scaled with diminishing returns.
- Solo time-trial race with server-validated payouts.
- Reputation gates on higher-tier cars.
- Daily login reward.
- Robust saving via ProfileStore (session-locked, reconciling).
- Basic movement anti-cheat.

## Deliberately deferred (see ROADMAP)
Traffic AI, head-to-head/drag racing, car customization cosmetics, crews/PvP,
full city map, mobile-tuned optimization pass, monetization products.

## Economy first-pass numbers (tune freely in `GameConfig`)
- Start: $1,500, 0 rep, own the RX-7.
- Race finish: +$650 (base+win) and +15 rep.
- Daily: +$300, +10 rep.
- Upgrades: base $500, ×1.6 per level, cap level 5 per part.
- Car tiers: Junk $800 → S15 $12k (50 rep) → R34 $45k (180 rep) → Hyper $250k (600 rep).

## Win condition / retention
No hard "end" — the chase up the tiers plus daily rewards and (future) leaderboards
supply the long tail. First-session goal: earn enough to feel one upgrade land
inside the first 10 minutes.