Walk through a world where you can walk both aboveground and underground! When you come across insurmountable obstacles, you can simply continue underground and vice versa! Mind the cliffs and the spikes and make good use of the boxes. If you hit a blue circle during your leap, it will reverse gravity. You will then go up or down very fast and you can continue walking on the 'ceiling' or on the ground. Try to reach the door in every level!
A / D or arrow keys = move around.
W or up arrow = jump.
Space bar = inverse gravity.