The game is amazing, I will say it is the hardest platform jumping game I ever played. the following are some thoughts after finishing the game.
It may feel really hard and it is quite confusing how to play when I started. it took me a lot while to dig out the tricks. Before I found the trick: throw head up and wait for the head drop a bit then you can perform a long-range right or left jump, I try a lot of ways to pass level two. and one of the attempts is really complicated. In order to perform the right jump, I have to throw the head up, then jump to catch the head in the air, then throw the head right immediately, then wait for the timing that you can perform the right jump and catch the head in the mid-air. I did it, but it is way too complicated. Even the attempt prove to be a failure. I am quite enjoying the process. There is lots of similar experience in the following levels. It is the first time that I found so many tricks about "jump". It is quite amazing this simple" head throw and jumps" mechanic has so much depth.
Amazing work but may not suit everyone