I found the controls a bit cumbersome, but it's easy to see the amount of work that went into this game.
The attention to detail on little parts of the game like how the character's body moves when looking around didn't go unnoticed. The thing that impressed me the most was the excellent lighting. Did you program this solution on your own, or is there some library you used? Were you using normal maps?
Either way, well done.
I think the controls could be tweaked to be a bit smoother (I agree with the other comment about WSAD and the space bar. Maybe W could be a contextual button that either jumps or climbs based on state?), but overall, a lot of fun. Great job