The shmup is a genre that's notoriously frenetic and difficult to master, but Ikaruga wasn't content simply to throw endless waves of enemies and bullets at players. No, Ikaruga upped the frantic ante by introducing black-and-white polarity. Switch to black and only the white bullets can kill you; switch to white and the opposite is true. Meanwhile, the same is true of your bullets' relationship with their targets. They don’t call it "bullet hell" for nothing.