Okay, I've played this one. Good concept.
I got stuck after removing the fan: I couldn't climb up there all way, but I was able to remove the grate and cut the wire. After that, while I could interact with the vent, it didn't seem to do anything (supposed to give me that blue thing, I guess?).
Also, in addition to larger hitboxes (and a reticle, optionally) I'd recommend the ability to run, at least. The character moves extremely slow, and it shows - especially if you end up opening a lot of doors, and have to meander back :)
Still, congrats on the game.