Quiz time: identify the next number in the sequence 1602, 1503, 1701, and 1404. Is it 1305? 1800 perhaps? Not according to makers of the historical city-building Anno series, whose next entry will be set in 2070.

The PC series focuses on specific time-periods rather than taking the longer view of Civilization titles.

Anno 2070 will be the first one set in the future, and its announcement trailer invites prospective players to choose between creating an ecological or industrial future, setting sustainability against mass consumption come the game's release later in 2011.

Opting to side with the tycoons brings immediate benefits and efficiencies to a city's wealth, whereas following the advice of the game's environmental faction ushers in a cleaner world.

The trailer can be seen at youtube.com/watch?v=iTZ8ID8a1dU or the official website, annogame.com.