Overall, great atmosphere and aesthetic. Interesting designs, the whole vibe is very appealing and PSX-ish, and I had fun with it in general.

Thoughts:

Camera. The mouse camera controls are very smooth and feel good right out of the box. I like the view axis lock, but I think there should be a button you can hold to stop and quickly look around like old games tended to have. Sometimes you do need to look down. Plus, it's a game about a big tower, you need to slow down and appreciate the verticality of it once in a while.

Controller support. Didn't work and I had to plug out my PS4 controller. Caused infinite spinning otherwise. If you're not going to support controllers fully, it would be best to add a toggle to turn off controller input to avoid this issue. I do prefer to play these kinds of games on a controller though.

Map. The oldschool map is cool and the ghostly overview of the whole area is a neat touch. Gives it a sense of place and context that's not obvious in-game. One suggestion, it would be neat to add a fading trail of 'breadcrumbs' showing your movement on the map, to help orient yourself. Or maybe an option to orient the view to where Erin is facing when it's opened.

Performance. I'm on a 144Hz monitor and the game was smooth as butter for the most part, but the game stutters fairly often when loading stuff. It's more jarring because it otherwise runs so perfectly. Perhaps more preloading needed to fight that.

Audio. Game sounds good, atmospheric. There are some audio panning issues. It seems like sounds get panned hard left/right when the originate from Erin, as if the audio "listener position" was right on top of the character or a right behind them. Very noticeable on headphones. I think you need to move it where the camera viewpoint is.

Combat. The rhythm of combat is solid and flows well when you get the hang of it, dodging and stabbing away and occasionally blasting them. The iframe pauses are a cool way to show you're avoiding damage successfully.

Enemies sometimes didn't fade away when they died. Perhaps because they're part of a group and they only fade away together? Wasn't clear on that. I think it would be scarier if they don't disappear at all. It would always be in the back of your mind why these guys are just kneeling down.

Hit feedback on the enemies is a vital addition. Can't live without it, would be a radical improvement no matter how rudimentary. Even just shaking without any animation, flashing, bleeding afterwards, something. It's a necessity in any action game.

The sponginess of enemies. I think it would feel better if the gun did more damage but had less ammo. Exaggerate the already huge handcannon, make it have a powerful recoil and slow rate of fire. Going hard on this would make it feel like a more meaningful decision whether to use it or not in a given fight.

I realised only in the very last few minutes that waiting a while before you shoot (or is it holding the fire button, or both?) greatly increases the weapon damage. Needs visual feedback. Maybe give the impression you're locking onto their vitals and that's why it hurts them more when you wait and take aim.

Reloading discards the magazine. Okay, realism, but there's no way someone would throw away a mag with bullets in it when their resources are so thin. IMO swap it out and keep the remaining rounds. If you get more mags later in the game, swap to the most full one first.

The wolves will bite the boss trying to get you, which is kinda funny. Really hurts them too.

That's about all that comes to mind! I look forward to the full game. :)

Edit: I'm dumb, I thought the game wasn't out yet lmao. Still!