Hi hi!
Thank you for playing/commenting!
I did try to get a gamecycle going at least and then added as much polish as I could but I have to admit the one thing I struggled with was deciding how much and what kind of user feedback I wanted for certain things. It seems that feedback on rhythmic rewards is a thing I missed out on hard :D Either way, for each x streak you get, a random button spawns; the amount of streak needed for the next bonus button goes up by one for every bonus you earn, is the idea :)
As for the coin, oops! I guess both a powerup and a coin spawned on top of each other at the same time (with coin being just a millisec before a powerup)? :D That's something I hadn't kept in mind haha, I'll keep that in mind in case I decide to finish the game one day!