R-Type Leo is an arcade 2D side-scrolling shmup, the fourth game (although not considered a main entry) in the R-Type series. Rather than the fight against the Bydo Empire, the story background describes how a bio-computer malfunctions and takes control of an artificial planet that was built by mankind. The player tries to stop it with his spaceship. Compared to earlier installments, some changes have been made regarding the weapon systems. The Force and the Wave Cannon are removed, instead, Bit Devices are introduced that are comparable to the TOZ in Gaiares. Their firing direction depends on the movement of the ship itself. They can also be detached for direct collision damage to enemies. R-Type Leo is also the first game in the series with two players co-op.