When you turn on the Moon Gravity cheat in Grand Theft Auto 5, it takes longer for you to reach the ground during a jump. This impacts all jumps, whether you're on foot or in a vehicle. If you head up into the hills and find a nice jump for your car, you'll get a ridiculous amount of air time, or you can simply jump while on-foot and do some cool flips. Check out our video of the cheat on the Prima Games YouTube channel.