Unlike the main story of BioShock 2, the player does not take the role of Subject Delta but controls another Alpha Series Big Daddy taken out of hibernation by Brigid Tenenbaum just before the events of BioShock 2. She wants the Alpha Series to take ADAM away from Sofia Lamb in an attempt to foil her plans.
Each challenge requires the player to protect a Little Sister while she drains ADAM from a corpse using a specific set of weapons, Plasmids and Gene Tonics unique to every trial. Each level has three trials which can earn the player one, two or three stars for completing them, with a corresponding difficulty level. Earning stars unlocks new trials for the player to complete, and new unlocked concept arts or movies in the gallery. All difficulty levels on all stages must be completed to unlock the 36 star total.