Definitely one of the most enjoyable games I've played so far in the jam! I like the speed, the art, the different mechanics (orb that makes you jump again in the air is golden!). Only music was a bit annoying, especially after losing so many times :P
I wasn't bothered by difficulty at all, though I wish I could continue from where I left it last time! (didn't finish it). My only issue was that if you where near the edge of a platform and tried to run&jump, jumping wouldn't work so you'd just run and fall down. This is a common issue in small platformer games, I think, and I'm sure nailing the movement in these situations is hard, but it'd just feel perfect for me if you solved that. Wasn't too much of an issue though, so I still gave 5 stars on design. :-)
Great job, well done!