Try to guide the balloon and the wheel to the finish. Watch out for the sharp obstacles that can burst your balloon. Sixteen funny levels that you'll surely want to complete all!
Use the arrow keys to move the wheel left or right. If you press the up arrow, you'll get lighter, and if you press the down arrow, you'll get heavier instead. The first thing might be practical while climbing a steep ramp, the second thing can be useful when you arrive in an upward flow of air.