The Reapers have arrived. The Milky Way Galaxy has broken out into full-scale war, and Commander Shepard must go from recruiting squadmates to seeking the help of entire races in the fight against the modern-day Protheans. The Mass Effect trilogy will finally come to an end in early 2012, but can Shepard and crew defeat the massive Reapers and take back Earth in the process?

Mass Effect 2's final DLC, Arrival, set the stage for not only the galaxy's threat, but also the trial that Shepard has to go through back on Earth. Unfortunately, at the same time, the Reapers launch an attack on humanity's major cities, London included. What we saw in the E3 demo upon Shepard's visit was a futuristic depiction of Vancouver, Canada... as it was being torn apart by Reapers. While Shepard has travelled from the outer edges of the Milky Way to the galactic centre, Earth has been mostly out of the picture until now.

Recruiting an entire species may depend on Shepard to settle scores between alien races in ME3, or you could see some of your choices from the first two games finally have an impact. One thing is for sure though: Cerberus is no longer by your side. Were they displeased by your actions at the end of Mass Effect 2, or are they indoctrinated by the Reapers? Either way, this promises a good plot twist or two in the closing chapter.

So what does this mean for Jacob and Miranda? BioWare, of course, isn't saying, but we will be seeing all the major characters from the first two titles in some form. Liara, Garrus and many others made their way into screen shots and the demo, but it's unclear who all will be joining Shepard for yet another suicide mission. New characters, including playable ones, are expected to be introduced, such as a human Alliance soldier.

An appearance that has sparked a lot of speculation is that of Kaidan/Ashley, causing fans to wonder about a possible love triangle between you and your ME1 and 2 love interests. What would be spicier though - that, or a third romance? Yes, you'll get even more options in Mass Effect 3, including same-sex ones, for both male and female Shepard.

The demo showed a battle system that retained much of that of Mass Effect 2, but with key differences. ME3 still uses a cover system; fortunately you no longer need to be standing behind cover to be able to crouch. Shepard can dive and roll to different areas of cover, move while crouching, sneak up on enemies, and slice away with an Omniblade as new a melee attack. And if close-range combat is more your style, BioWare does plan to introduce a 'heavy melee' class just for that.

Xbox 360 players have a chance to put a whole new spin on their ME3 experience: Kinect support. The only aspect of this demo that we saw was voice recognition, which was used for both dialogue options and issuing commands to your squadmates during firefights. While this seems a tad unnecessary for the former, we could see that BioWare is going for a more immersive experience here. In the case of the commands, however, this feature seems useful, as voicing commands may be easier and not break up the flow of battle - the way that constantly pulling up the weapon and power wheels does.

With environments being even bigger this time around, it looks as if Shepard can interact more deeply than simply destroying crates. You'll jump over obstacles and gaps without crouching first, climb ladders and so on. The demo showed Shepard jumping on the back of a vehicle and using its mounted weapons to try to take on a massive Geth foe as the vehicle races through the city. Cerberus Atlases are mech-like vehicles that you can also take control of, even if they were only enemies in the demo.

As evidenced by one of them dodging Shepard's Omniblade attack, enemies are quicker, more aggressive and smarter than before. You will, of course face a lot of resistance from Cerberus troops, and even see Husks of different alien races. And then there are the Reapers. No longer a myth, they are very real, very gargantuan and very destructive... but very defeatable, no matter how bleak things may seem.

We saw in the demo changes to both powers and weapons, which give you more options as to how you can evolve the way Shepard fights. Powers can be evolved more than once, along much more than just the two branches and in more areas than seen in ME2. Weapons are now customized and upgraded individually rather than by weapon class, and changing a gun's capacity and other attributes changes its appearance as well.

If you are still unfamiliar with the Mass Effect series, producer Casey Hudson promised that there's no harm in starting with the final piece of the trilogy. This part contains the most important and exciting portion of the storyline, and BioWare plans to include something for new players that's similar to the interactive comic which PlayStation 3 players experienced when starting up Mass Effect 2.

Whereas Mass Effect set the stage for the overall story arc, ME2 was much more character-driven. But with all the emphasis on player choice, you will finally see all the dire consequences of your previous actions in the third and final chapter. Even your choices in Mass Effect 3 could have immediate repercussions, as evidenced by the heavy, somber note at the very end of our demo.

With Mass Effect 3, BioWare is creating an epic, large-scale conclusion to what quickly became a beloved and critically acclaimed RPG series. The Mass Effect team is clearly very proud of their work and was incredibly excited to show off a sample of this to the E3 attendees. How will Commander Shepard and his or her allies fight off the Reapers and save Earth? We won't find out until March 6th, 2012, but from what we've heard and seen, this last installment will be well worth the wait.