One of the better entries I've played so far!
I had some trouble at first but started to make more sense as it went on.
Q/E were extremely useful. Half the time I just T-pose and Q/E would get me through 50% of the walls.
Sometimes the walls seemed to come one after another and didn't feel like I had enough time to switch.
It would be nice to adjust the camera angle, sometimes it was hard to see if I would fit through or not just because of the camera looking down instead of straight at the target.
Overall really nice job!