There are few games that so define a genre that every other title to come out with similar qualities is compared directly to them. There was Doom, for first-person shooters, and EverQuest (and later World of Warcraft) for MMOs, but sometimes these exemplars of a given gameplay style, these genre-codifying works, fit such a specific subset of games that they drift, almost forgotten, into history.
Such is the case with the XCOM series, which has had its turn-based, granular gameplay aped by such games as Silent Storm and the UFO series. Now it’s back in top form with Enemy Unknown and, while the game itself won’t be out for another couple of weeks, there’s now a demo available for interested players with a Steam account (and who doesn’t have a Steam account these days?)
Should you find that you enjoy it, you can then pre-order the title on the same service, contributing to the perhaps-a-bit-unscrupulous tiered pre-order bonus system, which culminates in a free copy of Civilization V for all who pre-order.