The Citadel

It's so obvious dude was making a ryona fetish hentai game and halfway through he was like "wait a sec, I have a pretty good shooter on my hands now" and switched course midway. And I love every second of it.

The horrific anime girl violence sure is a vibe but this is actually a really fun shooter with good level design and music. It's worth the few bucks it costs if you can stomach the, ehm, aesthetics.

Pretty fun boomer shooter with unique gunplay mechanics, especially if you grew up with the OG's. Lots of reviews call it a "gooner shooter," but those are probably the same types who never watched Ghost in the Shell or Elfen Lied because they think even a minutia of exposed skin means people are gonna blow a load like they're Mount Vesuvius from the exposure.
I you enjoy good character/sprite designs, or a "show, don't tell," story format, this is also a good choice. If you enjoyed, be sure to check out the version 0.4 demo of it's sequel: Beyond Citadel

This game was deep in my memories. It seems so obscure, but it should be renowned the world over. It has everything I like: Guns, anime women, religious imagery, horrific gore, deeply involved gunplay, platforming, upgrades, sweet characters, and one of the most unique, efficient, and breathtaking graphical directions out of any game. There's some minor bugs, and I recommend adjusting the controller settings in steam input. After that, the game is a thrill to beat! The "easy" difficulty is at least as hard as classic DOOM's "Ultra Violence", so starting there will give you a very satisfying climb up the difficulty ladder.

starts off slow since you can't quicksave so unless you have extra lives any death sends you back to the start of the stage, which wouldn't be bad if the game starts you off very underpowered
once you do get more upgrades and weapons the gameplay is very enjoyable and the art is nice (even if it is a little unsettling since im 99% percent sure the anime girls getting gibbed is the dev's fetish)
easily recommend if you like anime and like boomer shooters

I'll address the elephant in the room. Is this a coomer boomer shooter? Not really. Aside from the main character there isn't much fan service in The Citadel. If anything, it's anti-fan service. It's eerie, grim-dark, and very violent. While enemies do appear as anime girls once killed, their guts are very detailed and the remains have horrified looks on their faces with tears rolling down their cheeks. There's almost no story within the game and it ends very abruptly. You have to search for it on the internet for some reason. What you can find is pretty interesting, at least.
Gameplay wise on one hand it seems to be a boomer shooter with double jumping, no fall damage (outside of instant death pits), no hitscanners - all projectiles, on the other you have iron sights, weapon recoil, leaning, and even manual and tactical reloads, as well as headshots... and then you pilot a mech and start blowing sh*t up.
The Citadel looks like a Wolfenstein 3D clone, but many levels have a ton of verticality where the double jump is required. Non-stop cyan aesthetics of the maps, in addition to featureless rooms, make them tiresome quickly.
There's no tutorial; the developer doesn't inform you e.g., what food exactly does, you have to figure it out yourself, and no quick saving. Only checkpoints with a life system. Very annoying due to platforming with instant death pits.
Tremendous potential, especially the setting. Since the sequel is in development, I hope it's much better.

cool tactical shooter game but it does suffer from enemies being really far away and super high up just pinging you + the not at all subtle over saturation of guro fetish content