Cardbots are freely walking the streets, ushering in a new era of uncleanliness, forcing people into their homes to watch the streets fill with rubbish. And it's up to you, of the Royal Janitor Strike Force to sweep the street clean of this filth.
In RJSF, your main weapon is fuelled by rubbish, and rubbish is dropped by enemies when they die. So you can use Alt-fire to suck up any rubbish dropped which adds to your ammo pool.