The decision to change a normal platformer jump mechanic to a floating, hard-to-control arc inflates the difficulty artificially without contributing anything to the game. The levels are exquisitely designed, I just question that directive choice. Even falling in a straight line, or landing where I expected, became a challenge, especially in later levels where a combination of cannons, spikes, and thin pillars meant precision was needed.
The wall-jumping ability somewhat makes up for this initially, as if I 'messed up' I could still jump off of the side of the block I'd intended to land on, but once spikes on the sides of blocks came into play, I was crippled not by the level, but by not understanding how the square was moving. Sure, if I had exact timing I'm sure I could control it, but with human reflexes, I'd find myself hitting the same buttons at approximately the same timing and moving in a COMPLETELY different way due to the floating.
In other platformers, even those where precision is perilously exact, using approximately the same timing gets you to approximately the same space. The floating of the block meant that I'd completely overshoot or undershoot where I wanted to go, trying the exact same button combination (jumping forward, then frantically adjusting between left and right til I got the right adjustment down doesn't even work because of this).
Music also great.