Support keyboard and pointer
For a technical producer, this inventory delivery prototype should make every player action and player-visible outcome easy to evaluate. Write how to connect successful purchase to a visible owned or quantity state. Map preview, confirmation, cancelling the action, an insufficient balance, pending, success, delivery, owned, and reload. Give every failure a safe next action. Check tab order, focus indicators, mouse targets, escape behavior, and the return to game controls. Confirmation must never borrow an input that also performs a high-frequency gameplay action.
Plan for wide layouts
Keep the item, Koin amount, balance effect, and actions together on common desktop widths. Avoid pushing a player cancellation off screen simply because the game canvas occupies a large area.
Test window changes
Resize, move between displays, zoom, refresh, and restore a background tab. The interaction should preserve the selected item and resolve pending or delivered states without another grant.
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 desktop web games. Desktop browser purchases remain Koin flows inside the supported experience.
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 desktop web games. Desktop browser purchases remain Koin flows inside the supported experience.
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 desktop web games. Desktop browser purchases remain Koin flows inside the supported experience.