Keep the brief portable
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. Describe screens, signals, states, and outcomes without tying the concept to a billing plugin. This lets a Godot team choose architecture after the player journey has been tested.
Plan export work independently
Browser behavior does not install store plugins, create native entitlements, or export approved binaries. Assign persistence, identity, platform APIs, security, refunds, and export testing separately.
Replay states in the Godot build
Once implemented, compare the same item definition and recovery paths against the prototype. Check scene changes, saved ownership, repeated input, and return from suspension without double delivery.
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, full price in Koin, and owned state. Consistent cards make differences easier to understand. Test that behavior using Godot prototype teams. A browser prototype does not install Godot billing plugins or export store-ready binaries.
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 Godot prototype teams. A browser prototype does not install Godot billing plugins or export store-ready binaries.
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 Godot prototype teams. A browser prototype does not install Godot billing plugins or export store-ready binaries.