I can't for the life of me pass level 7 and I have no idea why - the projectile never travelled far enough at all so my comments will be based on all levels before that:
1) I want to give praise to your controls, it feels nice to play - polished and tight! Very responsive with the slash shooting. Very satisfying to shoot an enemy, rewind it back to you and slash it towards another group of enemies again.
2) Very simple but effective artstyle. Pleasant from the start all the way to the end of my session.
3) Great UI - especially at the main menu where you give us room to experiment with the controls a bit before jumping into the game. Kudos for good tutorial!
There are so much great things from the great game design that just makes this a fun game to play! I enjoy it!