Darker and more menacing in tone, Mass Effect 2 begins with a doozie - the destruction of the Normandy by a mysterious juggernaut that is, as Seth Green's Joker screeches through the comms, "not geth." (The geth being the synthetic AI race that chased you all the way through the first game.) The last sight you'll see before the opening credits roll is Commander Shepard's body beginning to burn up as it falls planetside from the wreckage of the Normandy. It's hard not to get excited with so dramatic an opening.

After the credits roll things get even more interesting - you'll find yourself working for the shadowy pro-human organization Cerberus, which you spent a lot of the first game fighting. There's a visceral reaction to be found in working with the 'enemy,' and I noticed myself snarling resentfully at the Cerberus-themed main menu, let alone the creepy new don of Cerberus and your techno-dungeon master, a fella with weird ocular implants named "The Illusive Man." (For the first few hours I was determined that his name was a spelling error, but lo, 'twasn't.)

Graphically, Mass Effect 2 erases the memory of the juddering aliasing and texture-clash from the first game. Every scene is rendered beautifully in fine-grained detail, to the point where I mistakenly thought several side missions were going to be full-on mega plot points simply because my shuttle landing was so ridiculously well-lit. Color is everywhere and there are no more repetitious cookie-cutter environments. Everywhere you go feels excellently well-done, from the skeletal ruin of an enormous battleship that teeters over the edge of a ravine (and actually does teeter, perilously, as you scamper about its ruined frame) to the former quarian colony now ravaged by a mysteriously hostile sun. In the latter, stepping into the sunlight burns away your shields - it's an awesome trick.

Voicework is stellar. Aside from the male Shepard, who says everything from a tender whisper to an angry appeal in a kind of robotic declaratory shout. It's not cute, but he is. Tricia Helfer voices the Normandy's AI, EDI, while Chuck star Yvonne Strahovsky voices Miranda, your bitchily-hot female sidekick and loyal Cerberus lapdog. The quarian sidequest features some of the best voicework, including my personal favorite Claudia Black and Oscar-nominated Shohreh Aghdashloo as two husky-voiced quarian admirals.

Choice is built into the game from the get-go, but whether you rant and rail against working for terrorists like Cerberus or willingly go to the dark slate-gray side, you'll follow a relatively specific path regardless - building choice into your characters reactions but keeping the spine of the story tight enough to avoid the middle-volume syndrome is a tight rope to walk, and for the most part Mass Effect 2 gets it right. (Lame, obvious cop-out answers about why a female Shepard has fluid sexuality but a male Shepard cannot aside.)

A species of hive-based bad guys has been destroying human colonies - and perhaps doing icky things with the colonists - and The Illusive Man has fingered Shepard to find out why and stop them. Naturally, Shepard suspects the Reapers to be behind it all - the enigmatic deep-space machine superbeings who previously sent one of their number, the starship known as Sovereign, to bedevil Commander Shepard in the first game.

While the bare bones of the plot are traditional space opera, and your mission largely consists of rounding up the baddest bad-ass team in the galaxy before tackling the badder-ass bad guys, a lot happens during what could otherwise easily have been a generic story: some questions that are addressed and perhaps even answered during the course of your adventures are big ones, like what really happened to the Protheans, what the other Reapers may be like, and some relatively subtle foreshadowing gets laid down for #3 - specifically tied to old legends about the scale of the destruction that the Reapers bring. If you keep your eyes and ears open, you might find some "stellar" hints.

Also rounding out the plot are the gloriously continued storylines from an imported Mass Effect 2 character - everything from who you chose to sacrifice on the planet Virmire to how you treated annoying Citadel reporter Khalisah Bint Sinan Al-Jilani will come back to haunt or help you, including longing looks from whomever you romanced the first time around.

The new party members (and some familiar faces) are for the most part extraordinary. Salarian scientist Mordin Solus stands out as one of the most interesting and well-developed characters I've seen in a game in ages. And he sings Gilbert & Sullivan, c'mon! Other party members such as the Asari Justicar Samara (think unnervingly wide-eyed samurai with boob-separating armor) and the sensitive Drell assassin Thane are also very well-done, and helping them on their own personal quests will earn their loyalty, a secondary outfit, unlock a special ability, and generally round out the story with a lot of sincere and emotionally affective moments.

The combat gets a major overhaul, coming closer to the third-person shooter "lite" to which it clearly aspires - you'll find yourself shooting off rounds and abilities from cover with a very accessible Gears of War style mechanic, and your AI teammates are actually helpful. Usually. Health and shields regenerate, and ammo is looted from your enemies. The stop-and-go nature of biotic and tech abilities is still awkward, and I can't help but think that there's a better way to be able to both pause the action and deploy your space-magic without having to do both at the same time - thankfully you can map several abilities to the shoulder and Y buttons, but there's still a pacing hiccup with the global cooldown.

Conversations run the same way they did in the first game, which is to say excellently. One minor quibble that remains from the first game is the context-shifting X button, which skips ahead the conversation under normal circumstances but changes to "default dialog option or quit dialog" just as the dialog option interface pops up - this seems unnecessarily frustrating, and I can't imagine how the game would have suffered if those two dialog functions remained mapped to two separate buttons.

Another quibble is how Bioware replaced the tedious vehicle missions with slightly-less-tedious planet-scanning missions. Instead of landing on the occasional planet and driving around painfully to get to your destination, you'll now simply scan the planets for any of four mineral resources (and the occasional mission) and then ping the hotspot with a probe to cash in. When a mission crops up, you'll land directly on-site, but random planet-based missions seemed much rarer this time around. The galaxy also feels somewhat smaller, although that may be because scanning planets - even with the needlessly slow and annoying scanning mechanic - takes up a lot less time than spending fifteen minutes trying to hump your rover over a mountain.

But you'll need them thar resources to build the armor, weapon, ability and ship upgrades you'll find scattered across the galaxy. It's an interesting way to streamline the RPG-ness of the game, and loot-happy gamers might not love it: as you find blueprints for upgrades, you'll construct those upgrades in the new Normandy's science station. And while some upgrades are for Shepard only, most of the armor, weapon and ability enhancements effect your entire squad. So while there's no more holding onto that useless krogan battlearmor, there's also no more finding that awesome krogan battlearmor.

You'll run into a few bugs along the way, but for the most part Mass Effect 2 takes the work of its predecessor and builds upon it with tremendous elan. Locations and hubs are more varied and alive: the clubs are darker, louder, and more fun; the merc hideouts are varied and fun to work though; even the Citadel is a less sterile place now that humanity's got a seat on the Council and everyone is still reeling from Sovereign's brutal assault at the end of game one.

There's no way not to recommend Mass Effect 2 to any gamer who enjoys science fiction or RPGs - I milked every possible moment out of the game and clocked in at just over 40 hours, and the dual DLC distro pipeline of the Cerberus Network and the regular marketplace promise a lot more to follow. Even if you don't want to slap down the cash, this game is worth a rental over a long weekend. Just be prepared not to leave your couch.

9 out of 10