Remember Hellgate: London? It was a near-future action-RPG set in a post-apocalyptic world shattered by an invasion of demons. The focus was on single-player gameplay but there was a strong multiplayer element to it as well, with PvP action and instanced, team-based quests. It was a cool idea (I thought so, anyway) but the execution faltered, and the servers were taken offline in early 2009. It was resurrected as a free-to-play online game a few years ago, but that didn't gain any traction with North American audiences either. Now it's taking a run at Steam.