Night is the time when zombies and all evil awakes and raise from their graves. This graveyard is full of evils, but hopefully, you've brought some powerful weapons with yours. Stop those waves by killing nasty creatures!
Have you ever thought about, how would Doomsday look like? If you think that everything will be in flame and people run in panic, then you are wrong. It will pass quietly, without anyone noticing, but then everything will be over. You are the only one who knows what would happen next, if nobody stops zombies. Grab your weapons and shoot them before they reach the tombstone.