Design for a shareable session
For a technical producer, this purchase confirmation prototype should make every player action and result shown in the game easy to evaluate. Write how to show the exact item, Koin amount, balance impact, and explicit confirm/cancel actions. Map preview, confirmation, a cancelled choice, a Koin shortage, pending, success, delivery, owned, and reload. Give every failure a safe next action. Assume a player may open the game from a link in a new browser with limited prior context. Put item identity, Koin balance, and the return route inside the playable experience.
Handle tabs and navigation
Try refresh, back navigation, a second tab, and returning after the page was suspended. A browser interaction must not imply native-store ownership or silently repeat a delivery action.
Keep canvas and interface coordinated
If the game uses a canvas, make focus, keyboard input, scaling, and purchase overlays cooperate. Closing the choice should restore game controls without leaving hidden buttons or trapped focus.
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.
Repeat the complete choice
The confirmation should repeat the selected item, exact Koin amount, current Koin balance, remaining balance, and ownership rule without introducing a different offer. Test that behavior using HTML5 games. Browser delivery does not prove native store billing or platform approval.
Separate confirm from cancel
Use distinct actions with clear labels and enough spacing for the target input method. Returning to the game should never spend Koin. Test that behavior using HTML5 games. Browser delivery does not prove native store billing or platform approval.
Prevent repeated confirmation
After confirmation, show a pending state and disable repeated input until the result is known. A slow response should not create duplicate grants. Test that behavior using HTML5 games. Browser delivery does not prove native store billing or platform approval.