their units and buildings. The sharing of resources, however, can be as simple as the system used in the Contra games (and other shoot-'em-up/beat-'em-up games) where a player who is out of spare lives could "steal" a life from the other player so both players could continue to play at the same time. Role of the second player The role that the second player takes upon joining a game differs from game to game. Most co-op games have the second player directly take control of another character that is usually subject to the same rules as the first player (i.e., a separate health bar). Some games, like Super Mario Galaxy, the Wii version of Prince of Persia: The Forgotten Sands, Super Mario Odyssey and some versions of Transformers: Revenge of the Fallen'', however, limit the second player to an omniscient, invulnerable (and sometimes disembodied) helper role, who then moves along with and assists the first player with abilities that he/she usually lacks. This may include the ability to attack enemies within the first player's view, typically via a targeting reticle. Other co-op games such as It Takes Two and Evolve give the other player special roles, tasks or abilities. Video games with co-op mode Asynchronous co-op mode Asynchronous co-op games are becoming prevalent among mobile platforms like smartphones and tablets due to their low-bandwidth requirement. Examples include Glu Mobile's Gun Bros and Gamevil's Zenonia 3. Asynchronous cooperative games upload only the character details to the server. During co-op gameplay, the server sends another player's character details, which are then controlled by the local AI. See also Player versus environment References Video game gameplay Video game terminology