First and foremost, the art in this game is beautiful (especially the character sprites)! It amazes me that all this art was completed within the span of 3 days. Cute voice acting as well.
As for the gameplay, it took me far too long to figure out the full extent of the freedom that the player has, in moving the character (maybe this could have been made more clear from the start). This freedom does add some spice to the gameplay, as you are able to perform maneuvers to slow down before an obstacle, and move the mouse very far to make a leap over large puddles.
As others have pointed out, the hitboxes do feel a little funky, on top of the fact that obstacle-hits stack quickly, which, at times, makes for a quick death (some invincibility frames would have been nice in those instances). Maybe this is the game journalist in me, but perhaps a full-reset of the lives would have been nice, whenever the character travels to space.
All around, this game is a gem, and I sincerely wish it makes the top 20.