Pros and cons are down below) Check out my vid here (the game is the 2d there, likes and subs are highly appreciated)):
Advantages:
1. That was something new! It had SCP containment breach vibes, of course, but the game was still original in every way possible! The mechanics (though simple) were rather appealing - the fact that the character had several lines for reporting using a walkie-talkie (or whatever it's called) for the same sighting is very cool! (especially enjoyed "oh f*ck" ones at the end))
2. I loved the story and the details in the facility. Enjoyed reading the notes on the walls and it's so nice that the game gave you just enough time to do that. The moment (and the note) with the cups was amazing! Such a cool little detail. Like, yeah, they have also escaped, but I have bigger problems over here.
3. I think the ending was cool. I think it was perfect. A little bit of irony always makes the story a bit spicier. I think that it wouldn't be as great if you'd finish it after the neutralization of the entity.
4. Voice acting!
5. The game saved progress on each floor so even if the player woul'd die - they don't have to replay the whole game again.
Disadvantages:
1. Well, the hints at the walls don't really make sense as the entity kills almost immediately (as one can see upon failing the game). Who'd leave a note for the only other fighter so high on the wall in a dying state. I know that this is a bit nitpicky but that's what I thought when I saw these bloody notes on the wall. Maybe it would be better to let someone scream that before dying before the main character's eyes or something like that in order to keep the immersion.
2. I also didn't really like that we are constantly going down but the floor count is going up.
3. The entity can block the walkie-talkie signal but can't affect the elevator in any way? That was very weird. Maybe the game would benefit a lot from letting the character get stuck in the elevator at some point for a brief time (it would allow them to comment that and explain why the elevators are still going).
Overall:
Amazing! 5/5 definitely. It's a pity I can't rate the game on jam as I don't have my own submissions, I would like to help you out so much! That was great. It's obvious how much effort was put into the game (in such a short time) and that you thought about the players a lot and made everything to create a comfortable experience. Great job! Can't wait for more games form you!)
Hope my feedback was useful!