Amazing game! But there are a few exploitable glitches in level 2.
You can completely skip calli if you just wall jump (this is really good for the speedrunning achievement)
If you get Miko to 50% hp and the blackout appears, you can go to a different level, and the blackout stays until you die or beat miko. But imo you should keep this because it's basically another way to make the game insanely hard. (I managed to somehow beat holo hq with blackout, though lv 6 calli's blackout just makes the entire screen black until she uses the drop down attack) Picture for example.