I really enjoyed it!
I played the latest available version at the time, V1.1.0. The controls are pretty solid, it felt pretty good to control the character. Maybe it's because I used the updated version, but I never had trouble performing double jumps or any type of controls. I also really dig the artstyle.
But the thing I enjoyed the most was the unlockable powers! It gave the levels an exploration element, serving as a reward for taking a different path. Almost metroidvania-ish. I actually was a bit disappointed that I only found 3 powers total (+ 2 MP increases), are there more? I was really looking forward to finding more movement abilities, but there don't seem to be any. Maybe an extra 3rd jump, or a special type of jump, or running or whatever. Also, the 2 attacking powers I had (fireball and the basic attack you start with) end up feeling a bit similar. Which is fine! They still had noticeable differences. But I was looking forward to another offensive power that had a different trajectory or behavior, instead of just "single projectile moving forwards".
I found a small bug where if you land just as your projectile animation is done you shoot a second projectile without having to wait for the end of the animation (and I'm pretty sure it doesn't consume MP!). But it's minor.