It is a 'dual analog'-style platform shooter, where you can aim freely around. Zombies spawn in waves, and killing them all sends in a new wave, with later waves bringing more powerful zombies and every few waves even a 'hulk' boss monster. Killed zombies grant experience points and drop money and occasionally a power-up. Money is used to purchase new weapons at stations strewn over the map as well as unlock doors opening up new parts of the map.