Design for touch and small screens
For a game product manager, 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. Define the player need, item scope, ownership rule, Koin price, and free path. Check age context, accessibility, rights, and platform expectations. Use comfortably separated confirm and cancel controls, readable Koin amounts, and a layout that survives portrait, landscape, browser chrome, and an on-screen keyboard without hiding the item.
Expect interruption
Simulate locking the phone, changing tabs, receiving a call, and returning with a slow connection. The player should see one understandable result and retain a safe route back to play.
State the platform limit
A mobile browser prototype is not an App Store or Google Play binary. Native billing APIs, device identity, refunds, entitlements, and submission need separate implementation and review.
Write the decision before the feature
State which player problem the item addresses, why a purchase is appropriate, and what evidence would cause the team to drop the idea. The prototype supports a product decision; it does not forecast revenue.
Compare free and owned journeys
Ask testers to complete the same goal with and without the item. Look for comprehension, pressure, fairness, and delivered value rather than using purchase completion as the only measure of a good experience.
Set the release boundary
Review age context, accessibility, localization, rights, moderation, platform policy, refunds, support, and security with the responsible owners. Keep unverified native capabilities and financial reporting out of the public promise.
Compare items consistently
Use the same fields for every offer: preview, benefit, ownership or duration, precise Koin price, and owned state. Consistent cards make differences easier to understand. Test that behavior using mobile web games. Mobile web is not the same as an App Store or Google Play binary.
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 mobile web games. Mobile web is not the same as an App Store or Google Play binary.
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 mobile web games. Mobile web is not the same as an App Store or Google Play binary.