Couldn't get past level 4. My tactics was wedging myself in a position that I can shoot from and they cant.
Whats with the optimization. My computer started sweating after a few rewinds and it is a powerful machine. What is your level reload procedure, are you deleting the entities from the previous attempt or are they still running in the background?
Anyway really cool rewind. You should definitely add a thumbnail and screenshots to make the game more welcoming (no thumbnail games get less clicks)
Edit: A timer and an exit menu would also be appreciated!