Very nice submission!
Overall nice level design, introducing elements slowly. Colors are pleasant and harmonious.
I love how you used time to make this engaging and challenging. Also the music fits very well with the pace of the game.
The only thing that I noticed is at some level the enemies start going sideways. Maybe it would be nice if they would be differentiated so that you know they are different than the usual ones (different color/sprite). Or maybe a visual aid to know where they jump because it's too fast without practice.