Really pretty, really cool concept (it's funny how we both though about "robot with a grappling hook" and then went on totally different directions), a tad too difficult for me. For some reason I couldn't grapple the finish line of the first level and had top try a lot until it worked, and I don't know what I did differently... I even went to read the comments to see if anybody had the same problem.
That said, it's one of the most polished and well executed game I've seen as of now, good job!