Fun idea! There is definitely a fun concept here, though the game play is a little shallow as there isn't any variation as you continue to play. I was jamming out to the music though, good job over all.

I see the concept you were trying to get to and like the idea. But in the current state the influence of stars either red or green is not enough. Even on higher difficulty. A possible way to fix this is by giving them more power including radius. Make them more powerful and make the player movement less powerful. This way the player is dependent on using the stars to their advantage.
In addition the hitbox of pick ups is a bit small for my taste.
Good job for finishing the game nonetheless! Just needs a bit more tuning