The goal of the game is simple: drive (pilot?) your taxi cab from place to place, picking up passengers and packages, dropping them off where they need to go. What makes things interesting is the fact that you're not negotiating city streets but the far more challenging environments of air, water, and space across 15 different levels. The various levels are made up of twisty cave-like routes, floating taxi platforms, moving obstacles, and even mines. Your cab is equipped with vertical and forward thrusters, and each type of atmosphere responds quite differently to them. The bit of vertical thrust that lifts you off the ground in an air environment might send you through the roof in a space environment. It's nicely frustrating to work with these rather different sets of physics while trying not to crash into a cab platform or a mine.