This was good!
It took me a few tries because I'd randomly get ambushed.
Sprinting shouldn't count towards a lose condition. Maybe you could add a stamina meter so sprinting still has a consequence.
It's also impossible to tell where footsteps are coming from. More accurately, it's impossible to know if the footsteps are on the same floor as you, or above/below you. This makes the footstep noise almost meaningless in the context of a stealth game. My recommendation would be to mute the footsteps of other students if they're not on the same floor as you.
Also, You should probably fix the x button making the player freak out and clip through the floor. It's probably a debug command, but it should be further away from WASD. I kept accidentally tapping it and having to restart.