Just finished Mass Effect 3 in about two days (20 hours). Rushed through it like a Call of Duty game. That said I went in there assuming the worst, with all the negative feedback the game has been getting.
For some reason I enjoyed it. A lot. I enjoyed it without the hype, without the marketing, without hoping for some kind of mind-blowing revelation at the end. The game, by itself is so well crafted. It has some issues here and there like every other game (the cover system needs work) but that's about it. Overall, this still has what made the other two games great, particularly the dialogue system and the fantastic cutscenes. With this game, the cutscenes reach a level well beyond Square Enix's efforts with their own JRPGs.
Now, to the main issue at hand (with most people anyway). The ending. I liked it. It's unfortunate people didn't like it, but based on what I've seen i think a lot of people are imagining going to conventions dressed up as characters from the series, enjoying future books or games or whatever might be made that's Mass Effect related.
The ending totally destroyed that possibility. Stop reading now if you don't want to be spoiled.
I believe the end of the game is really about the end of technology. Why do we have it, and what happens if it goes too far. The game always talks about AI and synthetics and themes of genocide...these are all things possible through technology. If I had to interpret the whole storyline of Mass Effect in a short paragraph, it would simply be this:
So the very, very, very first civilization in the universe advanced so far as to create synthetic life. But this created conflict and this caused a war between organics and synthetics. The synthetics won, but because they live basically to serve the organics, they create a system to keep order in the universe. When a civilization advances too far as to create synthetics again, the very first synthetics swoop in and destroy that civilization. Why? To 'save' them from destroying themselves. It's a strange way of seeing it, but to a being that only thinks about keeping order and stopping chaos (essentially the aim/purpose of technology itself), eliminating an advanced organic civilization is the best way to maintain order in the universe. I think the Reapers saw Organics as beings with a pointless existence, they're there and all they do is cause war and discord. So to prevent them from doing that, to 'save' them, they kill them off. It's strangely logical if you think about it....to prevent war, you prevent the things that cause war. If organic life is that thing....then flush it out so there is 'peace' in the galaxy. It's an all or nothing point of view that only a machine could possibly have.
Okay, that's more than a paragraph.
Anyway, so this cycle happens over and over for about several ker-trillion years and eventually with Sheperd they somehow manage to stop the cycle. There would be no more reapers and civilizations throughout the galaxy would have to start from scratch (given all the technology is destroyed in the end). It doesn't guarantee that it all won't happen again, but all the civilizations that survived the war get to go on living, which is essentially the victory that they aimed for in the first place---survival.
I liked it. I guess I liked the idea of this enemy that has existed since the dawn of time. I liked the idea of these synthetic beings (the Reapers) seeing that destroying all organics is the only way to preserve peace...maybe to me it seemed they were partly right. There wouldn't be any chaos on Earth today if it weren't for mankind. It would all boil down to survival of the fittest among species, but I doubt you would see natural creatures destroying the world on their own. Humankind is fully capable of doing that, thanks to technology. So to save the world, you'd have to take out mankind....which is insane because who'd be there to enjoy the peace? But in this concept of peace, mankind is the least important aspect of it....so long as there isn't anything that can cause chaos or discord, that would be 'peace'...at least, the way a machine would view peace.
So yeah, it's complicated. That's why people hate it! And that's why I love it. It's very 'sci-fi' in the sense that you have to think about it. Not a lot of people normally do that when it comes to games, so Bioware was pretty gutsy for going for this kind of 'artistic' ending. Now they have to bear the brunt of all the bad feedback, but I think they did a great job.