I enjoy the CRT aesthetic.
The music looping in the background was a bit harsh. It did fit the theme of the game in a way, so I'm a bit torn on it.
Gunfire sounds felt like they interrupted each other, so they were cut short, which felt off. Honestly, if there was an ear organ and this was happening, it would be incredibly theme fitting (i don't mean that in a bad way, your concept has some really cool potential).
The anatomical pixel art was stunning (and very eye grabbing, good use for the cover art) for the overall game itself having such simple art. It's an interesting juxtaposition - though if it was outside of a game jam I'd love the art to stay a bit more consistent.... this is VERY subjective however and I can see what you were going for and appreciate it (plus good god it must have taken you forever to draw something that detailed, seriously...from one pixel artist to another, it's very impressive!!!).
Juice levels were very nice.
The organ system reminds me of what Miziziz was doing with Wrought Flesh, but handled differently.
I'm a bit torn on the mechanics. They are clever, but they feel a bit unintuitive. I often got confused on which organs were which on the screen since they were small - and found myself referencing the page to see what they do a few times, halting the pace of the game.
Something about the systems of this game and the lack of progression just doesn't feel as satisfying as the rest of the games elements. I don't mean this in a harsh way - probably just my tastes in top down shooters.
Again, just an opinion and honestly even I feel like my critique is more my personal feelings that objective criticism at this point. Regardless of my feedback, you definitely put in some good work and produced something unique.