That slow motion function is really fun to use! The intro cutscene was really well done, I agree with the comment about making the transitions between each scene/panel of the cutscene a bit quicker.
I also found when I ran around for a bit and all of the enemies chased me, I could shoot an enormous amount of them in one go as they were all in a straight line facing me. This made the game slow down a great deal whilst the particles were spawned. Could this be limited at all?
Nice job!