I'm only okay at platformers and was playing with keyboard and mouse. I got a C on the tutorial and didn't make it through level 1. This game was hard, but it felt like it was suppose to be hard so it didn't really feel frustrating. When I stopped playing, it was because I acknowledged that I just wasn't skilled enough and not because the game was unfair or poorly made.
I personally found it difficult to control the character with A and D. I think it might have helped if I could have used W to jump, but trying to control A, S, D, Space, and Shift all with my left hand was a real challenge. Several times I switched to using the arrow keys with my right hand and Space and Shift with my left, which I found gave me much better control, but then I couldn't use the mouse for the gem dashes. I used wall jump a lot in place of the gems when I could.
I enjoyed the art. While the player was a simple design, there was still a fair bit of character to them. I was particularly fond of the way they looked when sliding down a wall. The movement in general was cute and sometimes it was fun to just run back and forth to watch.
I do think that this could be a lot of fun for people who enjoy fast-paced platformer games.