Something not working, or just want to say hello? Write to support@iparigrafika.hu and you will get a reply from the person who made the game.
It helps enormously if you mention which device you are playing on, which version of iOS it runs, and what you were doing when the problem happened.
Open the game, tap the lock on a level you have not unlocked, and choose Restore Purchase. The unlock is tied to the Apple Account that bought it, so make sure you are signed in with the same one. Restoring is free and can be done as many times as you like, on any device you own.
Game Center needs to be switched on in the iOS Settings app and signed in before the game can submit anything. Only single-player scores go to the global lists; two-player games are recorded in the local high score table on the device instead.
No. Progress, settings and local high scores are stored inside the app, so deleting it removes them. They are included in an iCloud or iTunes device backup, so restoring the device from a backup brings them back. Purchases are never lost either way — use Restore Purchase as described above.
Version 2.0 runs on iPhone and iPad with iOS 11 or later, and supports every current screen size. Two-player mode is an iPad feature, since it needs both players at opposite ends of the same screen.
If you would rather play along to your own music, start playback in your music app first and then launch the game.