The music fits really well and the sound effects are nice. The voice over in the elevator is also a nice touch.
The rendering style is nice, but the repetition of using 1 texture per level diminished this a bit.
As for the level design, It also felt a bit monotonic due to the square hallways. I think if more of the assets were shared among levels and maybe less levels (but with more elaborate level design), It would add a lot to the immersion and style of the game.
I like the idea of the glow stick to fend of the darkness. I bit more feedback on its effect would have been nice though.
Overall really nice execution.