Very nice first entry! I love the character design and animation! The controls are pretty good as well; personally I feel the jump is a bit floaty and the movement speed is a bit fast, but at the same time I think it works too! I think the biggest feedback with this entry is to just add a background to the world. Even if it is as simple as random dots for stars in the background, it will really improve the mood and feel a ton for such a simple addition.
I'm not sure what or if the white circles you collect are supposed to do. Also, I don't know if these white squares are supposed to be there or not...
All in all, good job on your first submission! Keep working and keep improving and keep learning and experimenting!