Very fun, once you learn how it's done. Only takes a few moments to figure out that you pick up forms as you go, and that you can't swap between them from the start. the use of picking up a new form while using the ability from a previous form is tricky, and punishing - more checkpoints could be useful around this advanced concept. I was also frustrated that a hard reset occurs during the timed segment while performing this complex maneuver for the first time, but that the wall-jump style vertical segment had no red-reset tiles. I hit the yellow tile that starts the timed segment mid-jump, and went therefor started the timed segment before I knew that there WAS a timed segment. lastly, when I completed the timed segment there was a block of text above a pit that I didn't get to read, because I passed through so quickly that I fell before I knew it was there. also, a hint about how to close the game once you've finished would be great: I ended up hitting alt+f4.
I like the concept a lot, but I was anxious that an obstacle or challenge would occur before I knew what it was, due to not knowing what the course ahead of me looked like. I'd love to see a segment with diverging paths, where there's always a way forward, but the course is different depending on which form you take.