Use simulated value only
For a technical producer, this inventory delivery prototype should make every player action and result shown in the game easy to evaluate. Write how to connect successful purchase to a visible owned or quantity state. Map preview, confirmation, a cancelled choice, a Koin shortage, pending, success, delivery, owned, and reload. Give every failure a safe next action. Treat Koin as a classroom game variable and do not request payment details, account credentials, or personal student information. The exercise is about interface states and responsible design.
Make the learning objective visible
Ask students to explain the item promise, free path, cancel behavior, failure recovery, and production boundary. Grade reasoning and playtest evidence rather than purchase completion.
Plan instructor-led testing
Run the prototype on shared devices with accessible controls and privacy-safe displays. Native billing, identity, durable storage, refunds, platform approval, and real transactions remain outside the lab.
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.
Connect success to the item
A success message is not delivery. Place the cosmetic, consumable, unlock, or upgrade in the screen where the player expects to use it. Test that behavior using classroom game labs. Use simulated Koin values and instructor review; do not collect student payment data.
Show ownership and quantity
Use owned, equipped, unlocked, or remaining quantity as appropriate. The state should match the promise made on the offer card. Test that behavior using classroom game labs. Use simulated Koin values and instructor review; do not collect student payment data.
Verify delivery after reload
Reload the prototype and return to inventory. The item should remain visible without subtracting Koin or granting a second copy. Test that behavior using classroom game labs. Use simulated Koin values and instructor review; do not collect student payment data.