Dang, for just two days, the precision on your controls is fantastic! Very well done! Short, sweet, and right to the point. This is an excellent proof of concept. The concept of replaying the same short section with bigger/different shaped characters is fairly unique, too. My biggest problem was the control setup. Z and X are super unintuitive placements for a game that requires active controls on WASD. A key that can be more easily hit by the pinky or thumb would be much easier to control, like L-Shift or L-Ctrl for dash and Space for jump.
Otherwise, you did great on this. Clean art and sound, too. Well done!