 Portal 2 includes bonus content, including four promotional videos, a Lab Rat comic, and an interactive trailer for the 2011 film Super 8, constructed with the Source game engine. A feature called "Robot Enrichment" allows players to customize the cooperative campaign characters with new gestures and cosmetic items such as hats or flags. These can be earned in-game, traded with other players, or bought through microtransactions at the in-game store.
