Amazing concept. 5/5
Tip for lv. 19: Build a ladder with your shadows.
Tip for lv. 20: Just jump over the edge and press spacebar repeatdly, eventually you'll to the other side.
You should be able to continue after level 15 to see how long you can last.
Btw I didn't have to do anything the last 5 levels or so. My lasers did the job :D
Yeah Sorry about that