You are Kerotan, a frog who works for Cat & Frog, a teleporter company. But lately your boss seems to be very stressed; a strange plague of black monsters seems to be infecting the company's equipment, and it is your job to fix them.

Kero Blaster is a 2D platform video game with guns. You can shoot left, right or up and you have a selection of weapons which can be upgraded at a few shops sprinkled around the levels. You can also buy extra health and lives at such shops. The currency consists of coins which are dropped by killed enemies.