Thank you so much for reviewing my game! :)
To answer your question, the game only penalizes you if you're not on rhythm ["bad..."], use the same sound too many times in a row ["stale"], or if you just spam all the keys
Otherwise it shows ["nice!"] if you're copying the host or ["funky!"] if you do something unique
I probably made the hit timings a bit too harsh
Also, I'd like to hear your thoughts on the unused song [Moe song.ogg in the soundtrack folder]
Sadly I couldn't have his level in the game in time [mainly because I'd have to implement bpm changes]