Like others have said, The ground detection isn't there so you can just keep jumping as much as you want!
However, on the two last levels you had the vertical bars in the way, and that immediately made me play differently. I started to get a kind of flappy bird vibe playing so maybe you could follow that gameplay Idea and see where that goes!!
Also the color switching is a decent idea but since the controls to move are the standard WSAD you should have the buttons to switch closer to those!