Really enjoyed playing your game! The graphics work nicely, and I love the rewind effect. The concept is really cool and creative!
I find the difficulty to be quite well balanced: it's hard but you want to get back to it, and the different phases make it so that I don't get bored and feel like I am getting better as I learn the paterns.
Anyway I'm going back to it, I almost beat it!
Edit: didn't talk about the mirror/ghost (not sure?) concept that is really really cool! like it's your ally, but also can hurt you, really new and fun concept.
Edit 2: Boss beaten :) Thank you for the game!