Welcome to Cubo 2. Use the arrow keys to move and jump. Press [R] to restart a level. All levels are 100% possible, but not all of them are very accessible. Basically, some of the levels are super difficult. >:D
Speedrun time: 1 min 56 sec. Watch the video here: https://www.youtube.com/watch?v=IHCcL0GV4Dw (BTW, I made it)