Soulstar for the Sega CD/Mega CD is a 3D shoot-'em up that combines several different types of gameplay into one game. Some levels are on a fixed path, similar to Space Harrier or Star Fox. Other levels allow your space craft to hover freely around a 3D environment, and in other levels your craft transforms into a walker robot for close-up attacks.
The player takes the role of Bryk Hammelt, a warrior pilot tasked with stopping the alien aggressor known as the Myrkoids from draining the Soulstar system's energy resources.
Gameplay involves navigating through various levels, fighting enemies and collecting power-ups while avoiding obstacles. The game requires quick reflexes and strategy to progress through its challenging levels.