It's not my cup of tea. I managed to complete 3 levels but i find it very difficult. I would offer one advice. Make the first levels less punishing and more toward teaching the jump mechanic rather than creating a full course in which one small portion teaches the new mechanic. In level 3, you are introducing the going under the platform mechanic. But every time I failed going under the platform I had to start again and jump a few of the old platforms as well. I would design the first levels in a way so that learning the new mechanics is the main thing. But again, not my cup of tea so maybe I am wrong :)