I like the general concept a lot. However, I found it pretty awkward. It was hard to tell what I was doing wrong at first. I think it would have been much more obvious in third-person, though that would obviously have a different feel. Maybe just some kind of tutorial or even a security video showing the player in the first area might helped?
The gravity also seemed a bit too extreme for walking. I think I would have preferred if walking was a bit more manageable and jumping was necessary but easy to over-do. Regardless, definite potential here. Nice job!