Use the Arrow Keys or WASD to move and aim your teleportation power. Press Z or SPACEBAR to jump. Your goal is to get to the door to escape each level.
Depending on where you're walking, if you are facing a wall or the floor, and the white circle is in open space, you can press X to teleport to the white circle. You will also rotate so that your feet land on the surface you just teleported through.
TIP: If something seems unreachable, you may have to jump, then when you're almost back on the floor, teleport to get a big speed boost on the other side.