Mary of Just Press Start writes:
"Parasitus: Ninja Zero (Developer: Heart Attack Machine) is a side-scrolling action game in which you battle zombie-like corpses, angry wolf/hyena type deals, and other interestingly perverse and difficult-to-identify creatures who are trying to make you dead. You’ll work your way through stages (which take place in different settings – castle, mountain top, etc.), and each stage has various levels. You’ll need to scale walls, wade through rivers, and dodge fireball booby traps as you face each stage and its peculiar inhabitants and bosses.