Metropolis Isle has been invaded by radioactive mutant bugs after an explosion in an ice cream factory. As one of the few survivors you must fight your way through hordes of bugs to face a final showdown with Bugzilla and escape the island. Luckily you're not alone and you can locate other survivors to help you in your fight for survival. Big Al, an enterprising individual, has even set up a shop where you can find all the supplies you'll need to make it through the city. Increase your firepower, stock up on grenades and even buy useful tools that might just keep you alive that little bit longer.