The more I play, the more gem rewards I get lol

I don't know about other games... But for this Marvel game, I haven't been playing for too long, and the 30-minute game rewards keep increasing lol After playing for 30 minutes, I got 16000 gems from a time quest lol Are there any other games with good rewards like this?? Is it true that rewards differ per player?? I checked out a game someone else screenshotted, but it didn't seem to apply to me ㅠ