I liked this a lot! The walls in the puzzles felt a bit weird at first, but after I played a few levels I realised there was a lot of room for nuance in play. For instance I can pass through thin passages by wildly flailing my mouse in vaguely circular motions (strafing didn't work quite so reliably, but...)
Or maybe that's an exploit, but hey, I didn't have to restart any of the levels! (X I really liked the feeling of a purified deer being on your side by protecting you as a wall, too, it feels a lot nicer than if you simply killed them.