(CNN) -- While many people still associate Facebook games with casual offerings like Zynga's "FarmVille," the social media giant has expanded its game catalog through titles like KIXEYE's "War Commander" and Kabam's "The Hobbit: Kingdoms of Middle Earth." Now, Facebook has partnered with start-up U4iA Games (pronounced "euphoria") to launch its first "core" video game, the first-person shooter "Offensive Combat." The game, which had a soft launch three weeks ago, has already attracted over a half-million players with no marketing. The game is playable as a Facebook App and included in the Action games section of the site's App Center.
@highlight
With "Offensive Combat," Facebook moves into core gaming with its first first-person shooter
@highlight
Traditionally, the site is associated with casual games like FarmVille
@highlight
Game is free to play, with "micro-transactions" for in-game extras
@highlight
Creators say it's age-appropriate for the site and more light-hearted than many shooters
"@placeholder is for people 13+ so there's age gating for that platform.