Really smooth and satisfying to look at. The normal jump vs. roll-jump dynamic is super smart as a way to control speed while still only using one button. Great job! I didn't see that there was a description of the moves beforehand, so figuring out that mechanic while playing was a fun discovery. I couldn't figure out why sometimes I didn't roll after landing a jump, though (might just be a bug?)
Contrary to some of the other commenters, I think the level of challenge worked well with the gimmick. I wonder if being able to look at a full view of the stage would help players formulate a plan ahead of time. That might make it feel less finicky to succeed.