For some time now, serious digital gaming on the PC has been dominated by one brand alone: Steam. And so it should be. No-one else has offered a more straightforward, integrated, transparent approach to gaming. Steam has made PC gaming infinitely better, and it’s conceivable that without Valve’s efforts, gaming with a keyboard and mouse would be in far worse shape today. But Microsoft, never content to back down from a challenge, are fighting back with their new iteration of Games for Windows Live. Games for Windows Live – or GWFL as it’s known – was always an attempt to mimic the kind of success of…