The visuals and the gameplay is awesome!
I believe that the controls could be a little tighter and more responsive, especially when climbing; some times when hooked on a wall the jump button does not work and you have to drop off and the re-try; something really annoying when you are on wall where you can die if you fall. I, also, suggest the acceleration and deceleration to be faster -higher friction, if you use physics-, so that the controls feel more resposive. Finally, I believe that there should be some tweaking on the wall-to-jump (towards the opposite direction) movement; it is really difficult to manage it properly, without falling...
Those are some suggestion I have movement-wise.
Oh, by the way, I would love to know more about the story!
All in all, it is a great game and I hope there will be more levels in different areas... Like a desert... I am just saying... ahem... ahem...
I will stick around to see how this project will evolve!
Keep up the great job!