Just at the start the game grabs you, first the ambience then it tells you to press spacebar. You do it, and the light appears and the game is there. Man, that's such an elegant way to present the mechanic, seriously. And it extends to the art assets, and specially the level progress screen. So nice, compact, and elegant!
The artist side of me is appeased. The animator side of me would like the feel of the movement animations and direction change to be a little less sluggish, but the artstyle still carries it through with no problems!
The game can certainly catch you if you get too into it while running from a monster and fall into some spikes. The scream startled me, hahahah. Though i'm not the bravest person around, i do think it means the atmosphere is good, hahaha.
Also really liked how you implemented that the floor can have multiple monsters. Got trapped between those two.
Overall, outstanding!
One other small thing: I actually thought that when a level lighted up, it was because i was going into that level, not that it was done. Foolish of me in hindsight, but it does mean i ended up expecting one more level and felt a bit anticlimatic, hehe.