Protect rendering performance
For a technical producer, this catalog design prototype should make every player action and clearly displayed outcome easy to evaluate. Write how to define item identity, value, Koin price, preview, and ownership before checkout. Map preview, confirmation, cancellation, too little Koin, pending, success, delivery, owned, and reload. Give every failure a safe next action. Open and close the interface during GPU-heavy scenes, then monitor input, frame pacing, and canvas recovery. A commerce overlay should not leave the game loop paused or controls captured unexpectedly.
Coordinate DOM and canvas state
Make the selected item and outcome visible in both interface and gameplay context. Handle focus loss, pointer lock, fullscreen transitions, and a resized canvas around confirmation and return.
Exercise context recovery
Simulate refresh, background suspension, and a lost rendering context. The player-facing purchase result should reconcile separately from graphics recovery and must never duplicate an item.
Name every state and owner
Separate preview, confirmation, pending, success, delivery, owned, insufficient Koin, cancel, interrupted, and reopened states. Assign later production work for identity, persistence, native billing, security, refunds, policy, and monitoring.
Define idempotent recovery
Repeated confirmation, a slow response, navigation during delivery, and reopening must resolve to one result. Record which state is authoritative and how the player can safely retry without another grant or Koin deduction.
Turn the prototype into tickets
Capture the visible behavior first, then create implementation tasks with expected examples for each transition and platform boundary. Do not translate a working browser interaction into an unsupported claim that backend commerce is complete.
Compare items consistently
Use the same fields for every offer: preview, benefit, ownership or duration, specific Koin amount, and owned state. Consistent cards make differences easier to understand. Test that behavior using WebGL games. WebGL rendering and commerce state need separate failure testing.
Keep the first catalog small
Start with one to three clearly different items. A large grid makes it harder to find unclear value, duplicated promises, and missing delivery states. Test that behavior using WebGL games. WebGL rendering and commerce state need separate failure testing.
Design owned and unavailable states
A catalog also needs sold, owned, equipped, and unavailable presentations. Do not leave a purchased item looking buyable after reload. Test that behavior using WebGL games. WebGL rendering and commerce state need separate failure testing.