I thought this was a broken game it first, luckely the comments said it works. So I went into the GDD and figured it out, but you really need a tutorial, or a description on your Itch.io page at least!
The game itself is cool, matching the colors to the enemies is a nice mechanic, the pulse also, especially when it goes fast enough to match the music (if you could always make it match that would be great).
Picking the colours was hard sometimes, and seeing when an enemy hit you too, there are a lot of visual clarity issues you could fix!
But nice project, it works and it's playable :)