I think the concept and gameplay is very well done. I only have a few complaints. I found that the screen is rather zoomed out and hard to see. Trying to find the targets and keep track of the angle of Oofoe I think would be easier if It were slightly more zoomed in. Doesn't have to be much but it felt like I was straining my eyes sometimes.
The learning curve is very steep and it was very difficult at first for a few reasons. When you swap from walking on the floor too flying how the controls work changes depending on the direction of the character, going right while running could make you fly left. I got used to this over time but I'm just talking about learning. I also think the controls were quite odd, in my opinion it would work better with one hand doing left/right, and the other hand doing jumping and breaking. Or putting jump on the Up arrow could work as well. I feel that putting one button on the other hand was slightly confusing and took a bit more learning compared to what I'm used to when it comes to movement (WASD)
The flying and level design felt really good and I enjoyed playing the game after I learned it. I think with a few adjustments to make it easier and faster to learn this could be great.