Cool game
I like the atmosphere and story seems interesting.
The heat mechanic was very cool too and especially liked that holding breath mechanic.
I don't know if I would call it a 3d platformer I feel like It's more of action adventure game but eh that's not that important. (maybe some people could be disappointed?)
The game runs a bit poorly (game jumped between 20 to over 60 fps , with average that felt like 30) I don't have newest PC but games with similar graphic style like "blue fire" run in 60 fps so I would suggest to try to optimize game a bit.
I got stuck for like 10 min at the first time with those monsters because I didn't know how to open that door, (maybe you can make it a bit more clear?) also there was a time I got stuck in a corner while escaping from a monster and I had to go to the menu.
Last thing, with that jump when that one monster chases you I didn't notice that there was a hole and I didn't jump so maybe you can make it a bit more noticeable.
Overall I like it and all the problems I had so far are nothing that can't be fixed