I finish the game today and I have a few things to say (my english is not the best btw)
1: great game.
2: I think the elevator puzzle in the lab needs more hints, since the solution isn't that obvious.
3: please don't reuse or overuse the enemy of the lab, for this I have a personal reason and a more technical reason, the personal one, is that I think it works more like a "boss enemy" than a regular enemy. and the technical one is beacuse it can become prety tiredsome after while (I tell you these since I got stuck in the elevator puzzle).
4: I would recommend to give more notes that give us a better understanding of the characters personalities, if you want to take the story more in the supernatural side, it's ok, this is just a recommendantion.
5: ok, the next thing is not much of a critique as it's a thing that a I would like to see, and it's as you can see in the part that I talk about the enemy in the lab, I have fetish for bosses, and it's that I think it would be cool to put more unique enemies like these. that serves as some kind of "boss", not exactly like the enemy in the lab, like I don't know make and enemy like the one scp that if you stop looking at it it would come closer, or if you think in putting a final boss you could put a puzzle boss fight, or even a normal boss fight, give the player a way to defend themselves and then take it away when the fight is over (and you could make that the weapon that the player uses in the boss have limited ammo, making it a little more scary).
sorry if I sounded kinda whiny, this just are recommendation that I think would make the experience a little better, but in the end you're the one who is making the game, thank you for reading all this big mess of a comment and I wish you the best of luck.