I suck at platformers, so prepare to wince. The purples and enemies in general looked good, except the cloaked-type character, I think their saturation was too similar to the background so it didn't look good. But maybe thats part of the cloak effect. I got confused after being revived at a savepoint and went the wrong direction for a bit. The glowstick throwing enemy has a nice arc. Players death animation is pretty brutal. I didn't realize you can shoot upwards (due to my suckiness). For the boss fight, it felt like sometimes the boss wasn't being hit even though it seemed like it should be. Also having to jump up on the boxes was tough for me because I kept wanting to double jump as soon as I could, instead of holding the button down for the full initial jump. Again I'm a pleb at these, so I never got the hang of it. Also the boss elements moved outside of the areas I was allowed to move through, so it felt like I was constantly getting gimped by the level geometry. But overall, nice, Im sure a veteran platformer player would enjoy it. I realized it didn't detect my controller because it wasn't plugged in, which probably would have made a difference, the z/x/c really sucked to try and use. Around 8:25 there is some kind of bug where I can't jump and shoot, however the ammo counter still goes down.
I think I had Vsync turned off for this build, so that may be why it was not displaying the flash correctly. Just know that as long as it is making that hit sound, you are doing damage.
Thank you for playing the demo and the feedback!