Wanted to get to this one after seeing it on livestream and now I finally have :D
This is good! It definitely has a few flaws, but once you get a run going you can get pretty into it. Considering the amount of store assets you used, I'm really surprised at how well all the visuals melded together. You could've told me they were all by the same artist/from the same pack and I'd have believed you. The audio's also all well done and befitting of the respective sounds/moments in game, nothing felt out of place. Those are two really good things to get right.
I have some issues with the overall gameplay. You pretty much need a run with the Q invincibility ability to get anywhere, and you need that on top of revive on death if you want to have a shot at the boss. The large blob enemies are simply too hard to deal with for how early on they are and how many of them there can be--you basically just die if you get a hallway with 3 and you don't have invincibility (or stunning lightning tbh) locked and loaded. There's definitely no upgrades that are totally useless, and there's a lot of credit to be given there, but whether or not you win is ultimately up to the luck of the draw. Bit frustrating also that you're able to move to the next room without collecting the upgrade, but ah well. On that note: the boss is way too hard. This could be a delta time issue (I had the same issue with the slasher ghosts, I do not recall them being that fast on the stream I watched, I have a 180hz monitor) but the boss is just constantly jumping to your position and you cannot dodge him. I promise you I tried. It completely comes down to whether or not you have enough health/revive on death to tank his constant damage output, and whether you have enough damage output to beat him quickly. I'm lucky to have gotten a run that won at all without grinding out the rest of the permanent upgrades (I only got +1 damage, I think for the length of the game the permaupgrades are a bit expensive)
But I can't say I didn't enjoy it! It feels great to play the moment you get a good ability, although you desperately need coyote timing on the character controller. It's completely cohesive, it all works together, I am very happy to have gotten around to it. Good job!