[Roadmap] Lottery spin after every tier

[Otaiki1]

Overview

Each time the player crosses a score tier threshold during a game, a Lottery Spin overlay interrupts gameplay briefly. A slot-machine-style wheel reveals a random prize before play resumes.

Status: Post-MiniPay launch roadmap.

Prize Pool Options

• Score multiplier — ×1.5 or ×2 applied to next 3 placements
• Revival token — stored, usable in the current session instead of paying $0.001
• Bonus points — flat +250, +500, or +1000 added immediately
• Cosmetic unlock — board skin or piece colour pack, available in the Shop
• Nothing — "BETTER LUCK NEXT TIME" (intentional, keeps mechanic honest)

UX Flow

1. Score crosses tier threshold mid-game
2. Tier-up banner appears (from colour modes feature)
3. Lottery Spin overlay slides up from bottom
4. Wheel spins ~2 seconds with escalating sound
5. Wheel stops on prize, displayed with animation
6. "TAP TO CONTINUE" prompt
7. Player taps → overlay dismisses, game resumes

Technical Notes

• Spin result is deterministic — seeded by current game seed + deal count for on-chain log inclusion
• Score multipliers and bonus points affecting final score must be in packed move data for spot-check replay
• Revival tokens and cosmetic unlocks do NOT affect on-chain score — local state only

Contract change required: Yes (if spin prizes affect final score)