Nice game. I like the amount of polish, and killing enemies is very satisfying. Perfect amount of game juice. The slowmo mechanic is well implemented but it would have been nice to have had some visual feedback that it was happening. I can see that a lot of effort went into things other than gameplay like the pause menu, the highscore system and the death screen. This is also the first jam game I've ever played to include a settings menu which is a huge plus as most jam games are very loud, and a volume slider is much appreciated.
The player was cute looking and even though the enemies are just triangles, there's enough juice in there for even them to look good.
Just as a question, did you use LMMS for the music?