The mere mention of the developer BioWare still brings a grin to many gamers, mainly due to 2003's Star Wars: Knights of the Old Republic, a remarkably deep RPG that single-handedly rescued the franchise from its sugary Jar Jar depths. After the satisfying chop-socky diversion of Jade Empire, the company is back, big time, with the truly gargantuan sci-fi shooter Mass Effect. Unlike many megahyped games that ultimately fail when it comes to actual playability (raise your hand, Assassin's Creed), this delivers on all conceivable fronts. Jesus Hopping Christ, what a game.

The plot: You are a hardboiled marine who must team up with a band of oddballs to stop a well-spoken bug-eyed monster from releasing a plague of fabled robotic destroyers. The fact that you're the hero of the story keeps players from descending to BioWare's usual baby-eating levels of villainy, but you can still choose to play as either a strict upholder of the law or a shoot-first, by-any-means-necessary galactic Jack Bauer.

It's tough, really, to get across how satisfying a package this is, ranging from the quality of the voice acting, the genuinely challenging combat sequences, some well-written narrative twists, and, most importantly, the overall sense of a fully realized universe. (Just reading the optional entries on the histories of the various alien races can kill the better part of a day.) Even the set-up process is a blast, with a process that allows you to choose different, story-relevant histories and a genuinely nifty facial editor. After a bit of fiddling, I was able to make eerie simulations of both Gina Gershon and Lee Majors. (Don't judge me.) As sophisticated as the trappings can be, though, the game blessedly never downplays its pulpy, space-operatic inspirations. An hour in, and you're already making it with a blue masseuse chick.

There are a few unfortunate bumps in the road, most notably the occasional graphic glitch, some initially counterintuitive squad commands, and the lack of any real tutorial level. For the most part, though, this is an honestly epic experience with a myriad of innovations (including the promise of regular downloadable missions and achievements that add bonuses to subsequent plays) that seem designed to use the 360 to its fullest. Pop it in and wave goodbye to hygiene.