Undertale on acid
I'm not sure if this game sells itself as a rhythm game, but as a fan of shmups and avoidance games in general, I thought the combat was pretty fantastic.
If you were really wanting to hit buttons to the beat play stepmania or something like Old School Musical.
But also play Bullet Audyssey for something similar to Everhood's gameplay.
Ending grind fucking SUCKED
I didn't babysit it 100% efficiently so it added another 10hrs onto the game time of just skipping through the final chapter.
Don't tell the player to look up the other endings online, but also have a trophy for seeing them all yourself.