Fun game. Nice and simple and teleporting is the main mechanic. I liked the variety in enemies and the boss as well.
If there's one critique I would say maybe keep the character closer to the center of the screen rather near the top. There were a lot of times where enemies would run in from off-screen and hit me and there's little time to react when you're so close to the top of the screen.
But besides that cool game. Good job!