Redwood City-based social games firm RockYou said this morning that it has acquired Playdemic, a social games developer based in Manchester, England. Financial terms of the buy were not disclosed. Playdemic is the developer of Gourmet Ranch, a title which has players growing organic food and building their own homestead. Rockyou said Playdemic will operate independently as Playdemic, a RockYou studio. Playdemic was backed by Ian Livingstone, the president of Eidos.