BioWare's release of Mass Effect back in 2007 for the Xbox 360 (and later in 2008 for the PC) meant a brand new science fiction universe for gamers to explore. Mass Effect went a little further than that, though. If you look at BioWare's history, a huge chunk of their games are using other licenses. Don't get me wrong: Baldur's Gate is awesome, Neverwinter Nights and its modding community were extremely compelling, and Knights of the Old Republic remains one of the better Star Wars games to date. However, it has left little room for original worlds. Jade Empire toyed with the idea, but Mass Effect fulfilled it. It's completely original, taking license only from the pure awesome of the space opera genre (and maybe Battlestar Galactica).

In the first game, you assumed the role of Commander Shepard, customizing appearance and first name to your liking. From there, you cruised around the galaxy in the most impressive stealth frigate ever designed: the SSV Normandy. It's the 22nd century and humanity is now one of the lesser powers amongst a big wide open galaxy of factions, the largest of which being the Citadel Council and its more prominent members. Humanity, as per usual, is struggling to be the best. The most significant appointment you receive as Shepard, aside from resident galaxy-saver, is enlistment into the Spectres. I could quote the codex here, but they're pretty much the CIA muscle of the Citadel Council. You spent the entire first game running up against a veteran and apparently rogue Spectre named Saren Arterius. He's allied himself with the geth, a race of violent and sentient machines, and the Reapers, a second race of extremely violent and monstrously sentient machines. Hollywood usually has enough trouble repelling one race of murderous robots, Mass Effect asks you to repel two!

BioWare polishes off its story-telling mastery at the end of Mass Effect by leaving us with one of the most fulfilling cliffhangers in gaming. You destroyed Sovereign, a vanguard Reaper bent on summoning the rest of its dormant race and bringing about another end of days. Saren is dead, and the geth fleet massacred. But the Citadel Council is forever changed, and its fleet is decimated. Humanity, and Shepard, saved the day. But somewhere out there in the dark intergalactic space between the Milky Way and the other galaxies, there's also the promise of legions of cranky Reapers, no doubt just as powerful as Sovereign. How are the squishy organics going to repel that?

Mass Effect was a great game, but it was very far from perfect. As a hybrid between third-person shooter and RPG, it couldn't decide which it wanted to be, and it didn't fuse the two genres overly well. Many things shined in the game: BioWare's Emotion Engine powers the conversation and characters beautifully. But it suffered from repetitive side missions, boring QTEs, and huge texture pop-in issues, among other things.

Many things have changed in Mass Effect 2, but many things have also stayed the same. If you've played Mass Effect, you'll be comfortable in the sequel. Firstly, there's been a noticeable upgrade to the character models and most textures in the game. Assuming the role of Commander Shepard once more, you'll give stink-eye to your enemies with an amazing level of graphical detail. The game is also filled with nice pre-rendered movies, far surpassing its predecessor, and this was probably the reason why the game required two discs. Despite the increase in graphical detail, I found much fewer problems with frame rate. My PC was able to run the game at an average of 50 frames per second, dipping only around 30 during the heaviest of loads. In other words: perfection. The game probably doesn't run that smoothly on the consoles, but it's improved in every way from Mass Effect.

The soundtrack for the game neither adds nor removes anything from the experience, and you'll find it similar to Mass Effect. On the plus side, Shepard's got a bitching new sound system in his quarters. Oh, did I neglect to mention? The SSV Normandy is quickly blown up at the start of Mass Effect 2, and Shepard is killed. Luckily, the rogue human organization known as Cerberus arrives and resurrects him. All it took was 22nd century science and half a trillion dollars. On top of that, they supply Shepard with a larger, more impressive version of the Normandy. The beginning of the game was jarring, and I was shocked BioWare so quickly destroyed what I felt I had earned in the first game. There is a silver lining to the loss: Cerberus forgot to give Normandy 2.0 a Mako, and the gaming world is forever thankful for that.

The whole pre-launch mystery of "The Illusive Man" and Shepard being "KIA" is solved within the first hour. Shepard is now borderline messianic and the Illusive Man, the nebulous head of Cerberus, is recruiting you. The Collectors, a highly advanced race of xenophobes that hide behind their one mass relay at the edge of known space, have been abducting entire human colonies and no one knows why. Worse: it becomes obvious it was a Collector cruiser that destroyed the Normandy and seems to haunt Shepard. After only a few conversations and it becomes obvious that BioWare has scored another win in the voice-acting department. The voice work in the game is just as good as Mass Effect, and usually better. They've even got a stellar cast of sci-fi regulars doing a lot of the work. It's impossible to play through the game and not recognize a couple people, unless you've kept your ears cupped for the past few decades.

Mass Effect 2 also delivers more competent squad mates, but more importantly, squad control is now where it should have been in the first game: you can order squad mates around individually. Combat is much more fluid now, and that's also due to a noticeable shift towards third-person shooter. I was able to control Shepard just as easily as I would control Marcus Fenix in Gears of War, and the improvements met up with my expectations. Enemies had better AI and took cover, often attempting flanking strategies against my team. The health system has also been changed from a simple health/shield variety to health, armor, shield, and biotic barrier. Each bullet slamming into shields or armor in Mass Effect 2 felt much more satisfying than chipping away at the tiny unreadable health bars of its predecessor.

The game hands over tons of fantastic improvements. Pre-rendered scenes of the Normandy's shuttle replace the Mako. Those boring QTEs that allowed you to hack doors, open containers, or mine for metals have been replaced with genuine, and addictive, mini-games. Mining has become probing, and each and every planet in the Mass Effect 2 universe can be scanned using a sort of Geiger counter. The player finds peaks in mineral concentration and launches a probe to collect them, gaining minerals for the Normandy based on the quality of the peak. Furthermore, minerals actually have a point in Mass Effect 2. Normandy 2.0 comes with a science lab, allowing you to spend minerals to upgrade Shepard, your squad, and the Normandy itself. It's a great addition to the game, and crucial to your success in the plot. Opening containers and hacking doors are also now accompanied by fun circuit-crossing and code-matching mini-games.

Best of all, the plot itself has received extreme levels of polish by the BioWare team. The writing is noticeably better than Mass Effect, and none of the side missions are repetitious. This is in stark contrast to Mass Effect, where there were only three or four different maps used for all side missions in the game. Conversations are as top notch as the first game, but they are improved even further by Paragon or Renegade actions; prompts that show up during some conversations. Accessing the prompt has Shepard perform a specific Paragon or Renegade action, which may or may not include kicking people out of windows or shoving drugged volus's.

I was a little irked when the game restricted where I could explore, barring most of the star systems from the first game. The shock of linearity was astounding, but within a few hours, the universe opened back up. The exploration mechanic is vastly improved. You now control a little Normandy directly as it throttles through solar systems from planet to planet. You buy fuel and probes from re-fuelling stations and plot courses at Mass Relays. Fuel is expended when you travel across interstellar distances within the same star cluster, adding further to the sense of exploration.

BioWare has made a few controversial changes to the game, however. The broad skill system from the first game is now chunked into more discrete blocks, allowing unused skill points to sit around for hours at a time. The differences between classes serve as both a blessing and a curse. On the one hand, it's good to have variety in class choices. On the other hand, some of the classes are underpowered. The Adept gets few weapons, no ammo powers, and can only use biotic powers against unshielded opponents. Other classes get many weapons and one or more ammo powers to start, and the change seems a little unfair.

The class disparity is worsened by the removal of the inventory and upgrade systems from Mass Effect. Not only does that mean the loss of two RPG hallmarks, items and customization, but it gives the player much less choice overall. You're bound to your class, and the only pittance the game doles out are the choice among several of an unlockable ability you can gain from crew loyalty. In Mass Effect 3, I hope BioWare takes another hard look and shifts back to some kind of happy medium between Mass Effect's customization and Mass Effect 2's fluid interface.

Despite its changes, however, Mass Effect 2 was a blast to play. With amped up visuals, audio, and gameplay, I had trouble abandoning the game for lesser ventures like food, water, or sleep. Mass Effect 2 is clearly about building up for the third game, and that's what you'll do. The actual missions against the Collectors are astonishingly short, and you'll spend most of the game's 30 hour lifespan recruiting the meanest, most skilled allies in the Milky Way. Once you've recruited them, you also get the opportunity to gain their trust by embarking on their loyalty missions and going along with their wishes. It sounds a little dry, but the game is executed very well. Each mission is different from the next, and everything feels fresh for the whole ride.

BioWare held up its promise of allowing you to import your save game from Mass Effect, and its effects are seen throughout the entire game. Supporting characters make contact and interact with Shepard in different ways. Just as it was with Mass Effect, the sequel asks you to make some difficult decisions in the final mission. Your commitment to gaining the trust of your allies beforehand matters, because they can and will die. But completionists like myself that like to hide in dark spaces and 100% everything aren't safe either, because spending too long grinding can have some shocking consequences too.

Although the sequel suffers a little from being the middle game of the trilogy and the stepping stone of the (hopefully) grand finale, Mass Effect 2 is extremely well polished and improved from its predecessor in almost every respect. There's tons of replay value in this title, for both Paragon and Renegade experiences, but also for variations of crew loyalty and ship upgrades. Mass Effect 2 is a very worthy sequel, and sets up Mass Effect 3 and the trilogy itself as one of the top science fiction franchises in the history of gaming.