Really hard game IMO. I don't like how it's easy to switch worlds back and forth just by holding the "r" key. You need to make it so that it only changes worlds when the player presses it instead of tapping it very quickly. The power-ups also need some explanation on how they work; the icons alone don't help. I didn't realize I could use the double jump in level 2 until I tried it out for myself. I made it to level 4 and gave when I had to deal with turrets that fired homing projectiles at me.