As GERALD (Gyroscopic ExploRAtion Landing Device) you must explore 385 screens of Hangworld, using limited fuel. The game is viewed isometrically, which means that the controls are rotated through 90 degrees - this, coupled with the fact that many screens have huge gaps and diagonal paths, means that it's hard to get far at first. Falling off ledges loses you time, which is very limited to start with.

Gerald must collect energy crystals throughout his journey - which can also be shortened by using a complex system of lifts. Sections you have travelled through are automatically mapped.