Kill 20 enemies with explosives in a single level.

Kill 5 enemies with one shot while in the AC-130 gunship.

Kill 4 enemies in a row with headshots in the single player campaign.

Kill the power.

Kill an enemy while blinded by a flashbang in the single player campaign.

Collect all Canopic Jars and max out your blood meter.

Clear out 20 Vampire packs.

Stake 20 hidden Firstborn vampires.

Unlock all powers.

Defeat Bloody Mary.

Return to the underground while no mission is active and travel from one end of the catacombs to the other.

Bite a member of a street parade.