Zybex is a horizontally scrolling shoot 'em up. The players took control of prisoners trying to win freedom from a galactic prison. At the end of each level they earned a crystal, opening access to the later levels of the game. The ultimate aim is to acquire the Zybex crystal which offers amnesty for the prisoners, Cassalana and Rinser. The weapon system constantly fires, and the fire button is used to change the current weapon. The basic weapon is the Orbiter, which the player always has. Picking up weapon icons increases the power of a weapon by 1 up to the maximum of power level 4. Dying reduces the current weapon by 1 power level, or loses it if the weapon is power 1 (with the exception of the Orbiter). As the weapons get more power, their fire rate becomes faster and the bullets stronger. The five weapons are Orbiter, 8-way (upgrades from 2 to 4 to 6 to 8 way fire), Railgun (powerful single bullet which gets longer) Pulse (fires straight forward and gains diagonal fire at power 3/4) and Wall (another forward fire, which gains size).