Support keyboard and pointer
For a game designer, this catalog design prototype should make every player action and result shown in the game easy to evaluate. Write how to define item identity, value, Koin price, preview, and ownership before checkout. Choose the offer moment, explain the game benefit, and protect the complete free path. Compare the experience before and after ownership. 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 cancelled choice 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.
Judge the offer in the core loop
Run the game without opening the purchase choice, then run it with the item. Compare pacing, motivation, difficulty, and recovery so the offer supports play instead of repairing frustration that was added deliberately.
Make the player promise concrete
Describe what changes on screen, how long it lasts, where it appears, and what remains available without it. Replace value labels such as better or premium with rules a player can observe.
Review the moment of choice
Check what the player was doing immediately before the offer and where cancel returns them. The item should arrive after enough context to understand it, but never during a time-critical or emotionally pressured action.
Compare items consistently
Use the same fields for every offer: preview, benefit, ownership or duration, clearly stated Koin cost, and owned state. Consistent cards make differences easier to understand. Test that behavior using desktop web games. Desktop browser purchases remain Koin flows inside the supported experience.
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 desktop web games. Desktop browser purchases remain Koin flows inside the supported experience.
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 desktop web games. Desktop browser purchases remain Koin flows inside the supported experience.