The green block is your main character and you use the arrow keys to control it. The goal of the game is to get to the spaceship, to avoid the lava (the red), and to avoid the monster. You can climb walls.
Every level is possible, most of the green block scripts I got from maciek-mario, and his project Pingle (a platformer). This is actually better than my original project Jumper (a platformer). There is a sequel.