Very brutal game and enjoyable game, but I pushed through to the end(608 deaths). It's got that one more try sort of factor that makes you want to keep going and when you get into a perfect sequence of swings it feels great.
I think a lot of the difficulty comes from having no control of the grappling hook or even being able to see it's trajectory, even towards the end I felt like I had a good grasp on where it was going but still made mistakes.
My only real complaint is that sometimes the floor detection was a bit funny where I would jump off a block but because I was so close to the edge it counted as my double jump.
Overall pretty addictive, nice work.