Technical producer focus
Turn the purchase into named states and transitions. Separate the player-facing prototype from identity, persistence, native billing, security, and refund work.
Technical Producer guide · HTML5 Games · Koin purchase UX
Technical Producer Guide to Koin Catalog Design for HTML5 Games
Use a playable web prototype to work through catalog design for HTML5 games. The goal is to make the player journey concrete before the team commits to native commerce implementation.
Create this game flow
Define the HTML5 games scope
Platform context
Design for the input, layout, interruption, and return behavior players expect from HTML5 games.
Prototype boundary
Browser delivery does not prove native store billing or platform approval.
Catalog Design in practice
Starting state
Show one item the player may decline, its preview, precise Koin price, balance before spending, and ownership rule in a layout suited to HTML5 games.
Main task
Write how to define item identity, value, Koin price, preview, and ownership before checkout. Keep each change visible to the player rather than hiding it in technical state.
Recovery
Make a cancelled choice, a Koin shortage, pending, interrupted delivery, and reload visually distinct, with a safe next action.
Role decision
Map preview, confirmation, cancellation, not enough Koin, pending, success, delivery, owned, and reload. Give every failure a safe next action. Use the prototype to resolve player-facing questions before creating platform integration tasks.
Solve the catalog design details
Design for a shareable session
For a technical producer, this catalog design prototype should make every player action and player-visible outcome easy to evaluate. Write how to define item identity, value, Koin price, preview, and ownership before checkout. Map preview, confirmation, cancelling the action, an insufficient balance, 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.
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 HTML5 games. Browser delivery does not prove native store billing or platform approval.
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 HTML5 games. Browser delivery does not prove native store billing or platform approval.
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 HTML5 games. Browser delivery does not prove native store billing or platform approval.
Prototype the player journey
1. Set the platform context
Choose the input and screen behavior for HTML5 games. State the platform limit beside the prototype brief.
Result: An honest scope
2. Map catalog design
Write how to define item identity, value, Koin price, preview, and ownership before checkout. Describe the player action and visible response at each point.
Result: A clear catalog design sequence
3. Add the Koin choice
Show the item, exact price, balance, confirm, cancel, pending, success, and delivery without payment-provider screens.
Result: A complete player journey
4. Apply the technical producer lens
Map preview, confirmation, a cancelled choice, a Koin shortage, pending, success, delivery, owned, and reload. Give every failure a safe next action.
Result: Technical producer focus
5. Test return and recovery
Interrupt delivery, repeat the input, and reload. The prototype should never grant twice or leave the player in an unexplained state. Repeat the test after interruption and reload.
Result: A stable prototype
Generate the HTML5 games prototype
Prompt 1
Create a shareable browser session for a technical producer. Focus the IAP prototype on define item identity, value, Koin price, preview, and ownership before checkout. Use a direct Koin item transaction with preview, exact price, confirmation, cancel, insufficient balance, success, delivery, and reload behavior. The technical producer must be able to name every state, owner, failure path, and expected check. Do not add subscriptions, payment-provider UI, revenue analytics, or native platform claims. State this boundary: Browser delivery does not prove native store billing or platform approval.
Prompt 2
Keep the item optional. Show its clearly stated Koin cost, available Koin balance, confirm, cancel, low-balance, success, visible delivery, and reload states.
Technical Producer test checklist
- The catalog design sequence feels natural for HTML5 games.
- The technical producer can make the intended decision from the playable result.
- The item, Koin price, and balance appear prior to confirming.
- Cancel, a Koin shortage, pending, success, and reload have different outcomes.
- The page states this boundary: Browser delivery does not prove native store billing or platform approval.
- Interrupt delivery, repeat the input, and reload. The prototype should never grant twice or leave the player in an unexplained state.
Limits for HTML5 games
- Browser delivery does not prove native store billing or platform approval.
- This guide uses a direct Koin transaction for one optional game item. It does not create a subscription or recurring charge.
- The result is a browser-based playable build. Native billing, identity, durable entitlements, security, refunds, and store approval need separate implementation.
- SEELE does not provide payment analytics, tax tools, payout reports, or guaranteed revenue through this flow.
Frequently asked questions
What does catalog design mean here?
Write how to define item identity, value, Koin price, preview, and ownership before checkout. The result is shown as a playable Koin flow.
Is this a subscription?
No. The player spends Koin directly on one named item or unlock.
What happens if the player cancels?
Return to the same game state without spending Koin or delivering the item.
What if the Koin balance is too low?
Explain the shortage, preserve progress, and do not deliver the item.
Does this include payment or revenue reports?
No. It covers the player-facing purchase experience, not financial reporting.
Is the prototype ready for a native store?
No. Browser delivery does not prove native store billing or platform approval.
Create the catalog design prototype
Open the complete prompt in SEELE, adjust the item and Koin price, then generate a playable version you can test.
Open this prompt in Workspace