 Upgrades to health, guns and magic are unlocked with skill points earned based on a ranking, which takes in damage taken, enemies killed and the length of time it took to complete a level.In the wake of multiple natural disasters culminating in a demon invasion in 2007, Earth has become a wasteland, and by the year 2013 humanity is on the brink of extinction.Alicia Claus, a witch guided by a demonic power dubbed the "Darkness", enters a near-deserted American city.