Hello there!
I enjoyed the atmosphere and setting of this game a lot! I do have some feedback for you though ( and I mean all of this with love!):
The slow-mo feels out of place with the pace of the game IMO. It feels like something that was added because you could add it, not because it fills a role in the game. I never used it, and the enemies didn't get to the point where I felt overwhelmed by them enough to activate it.
The player character is very OP. She moves too fast for anything to ever hit her and the eating mechanic provides a consistent amount of health so, even if you were hit, it wouldn't matter much.
A few things could help remedy this. First: There needs to be some kind of pressure enemy to allow the melee enemies to close the gap, Secondly: I think the eating mechanic should be changed (and if this doesn't fit your vision then absolutely keep doing your thing :)!!!). Instead of the viscera directly healing the player, maybe the guts/ vomit can be used in some sort of currency system where you use it to purchase health kits and ammo. Third: I think the vomit also needs reworked into somewhat of a "BFG" style escape plan or something of that nature. With these changes the vomit has more of a gameplay purpose, and it makes the player choose between having the currency for later or getting out of jail right now. Obviously this could be expanded upon, with the vomit or body parts being used for different spells. which brings me to:
If she is a witch or the like: GIVE HER SOME SPELLS! Replacing the slo-mo would be the best option IMO so that the mana bar still has some use. However, If you wanted to keep it as one of the spells, I would say the amount that slows down should be less (meaning the time is faster than in its current state) I personally believe some kind of blink spell would be more interesting over all! This should be a fairly easy migration behind the scenes if the item system mentioned above is implemented!
I honestly feel like this game would benefit from the pace being slowed down quite a bit. I could personally see it succeeding more if it had a slighty faster pace than something like Resident Evil 4. The spells and weapons would hit harder, ammo would matter more, and every hit would be agonizing!
Conversely, increasing the pace of everything would fix the slo-mo issue, but would make the puzzles/ platforming feel out of their element. The best advice I can offer about the pace (and this game as a whole): is don't try to be every game you can think of, be YOUR game! :)
finally a few minor things: I had V-Sync on and the game had some tearing still. The audio levels need adjusted, some times the guns felts too loud, other times too quiet. With the current pace of the game, the things you light with the torches take too long to light.
Again: I am giving you all of this feedback because I really enjoyed the game, I just feel like it is having a minor identity crisis. The guns, art, sounds and atmosphere were great!
I would also love to help develop the game. I don't have any experience in Unity or anything (yet), and I am not good enough in the 3D space (also just yet, I just finished college for it, but don't like 3DS Max so I am switching back to blender) to do any of that, but I would even help test! You can reach me on twitter @BigDoof12