Basically, new Keywarden bosses will show up in the four Acts of the game.

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But the vice president said the studies had not made "the next connection" - that game playing actually led to violent acts - and concluded that more research was needed.

BBC: EA boss denies video games encourage violent attacks

Facebook acts as middleman when Zynga game players buy virtual goods like tractors and electricity when playing Farmville and Cityville on Facebook.

FORBES: Zynga and Facebook: A Close Relationship Can Distort Revenue