Alternative titles being, "Beating a synthetic horse" and "Where everything is made up and the choices don't matter"
AVAST YE MAYTEE...SPOILERS AHEAD! (No seriously, MASSIVE spoilers ahead, do not read if you haven't finished the game!)
No seriously, this is your last chance!!!!!
Ok...are the children hidden yet? Good because the following boiling pot of game-rage might scar them for life. Well not really.
In all seriousness, I am among the ranks of many disappointed by the ending of Mass Effect; for the end of a trilogy that was proclaimed to finally put to rest the universe it fell more or less flat on its face. Ironically at the same time it did successfully put the Shepard story (and the setting) to rest. Just in a very unsatisfying way for most fans. The following is somewhat of a list of the aspects I found somewhat disappointing.
To be fair the ending did one thing reasonably well: it challenged its viewers to look beyond the current situation and take a long-view (albeit in a strange way).
Many are saying that this sort of ending is not new, this kind of ending came in Deus Ex Human Revolution. The difference is that Human Revolution had been building towards that sort of decision climax from the beginning; there was an obvious undercurrent of it throughout the story and the end decisions all were relevant to what you'd dealt with the entire time. This was par for the course as it had happened in the previous games. In the case of Mass Effect 3, the decision goes counter to everything you had worked for thus far....a new threat was suddenly created (exactly like one you'd already diffused earlier in the story) and you were given three seemingly asinine solutions with large plot holes (eg: Couldn't Blue/Green Explosion Shepard, now in control of the reapers, just have them rebuild mass relays? Why was Joker flying away?). In Mass Effect 2 the decision was relevant to what you'd just done; you took over the Collector base...do you keep it or not? You played leader throughout the base by deciding who played what roles. Mass Effect 1 did not have quite that discussion but it had an epic ending suitable for the story...you and half the galaxy take down a reaper. To compare the ending to Deus Ex Human Revolution, it would be like suddenly Adam was forced to decide the fate of humanity in regards to fusion research.
Even then, while the ending sufficiently closed the story it asked just as many questions as it answers: Who is this catalyst? Who built him? Why do the Reapers slaughter to harvest? What happens to the Reapers/Other-Characters after this? How did my squadmates magically end up on the Normandy? The list goes on.
Then there is the "choices" part...true to its word the game does ask you to make choices, but throughout the game and previous games the player had been asked to make important choices...we were lead to believe that these choices would eventually make a difference in the game. All those missions we ran during the main story of Mass Effect 3, all those relationships we made...all they did was boil down to a number for "Galactic Readiness". While you see the major elements you recruited, many of the smaller relationships or victories barely matter; you see a handful of Krogan, characters you saved along the way don't show up. I'll credit that some do show up: if saved the Destiny Ascension appears, the Quarians and Geth...but the rest hardly seem to matter.
In Mass Effect 1 and 2 the "BBEG" was a Reaper: Sovereign and Harbinger respectively, and while Harbinger set himself up to be the main bad guy of 3, you see him but once and he shoots lasers. In 2 he was surprisingly talkative, but suddenly has found himself without anything to say. At that, only FOUR reapers are actually destroyed in the game....three of them the new "Destroyer" baby reapers (and the only "real" reaper that "Dies" is only shown to lose an arm tentacle). The ending of 3 could have been as epic as 1 and 2, but instead they had a slow, awkward scene with Shepard walking around and not even getting to really talk to this Catalyst person.
Speaking of the Catalyst...that was perhaps the worst foreshadowing I've ever seen; they repeatedly make references to it, then suddenly it is the Citadel, and then its the ghost-brat.
Bioware's strong point has always been their characters; they might not make the most original stories in the world but they manage to make some very engaging characters. Show me some other NPCs that have the following of Tali or Garrus. At the end you see none of this, you just see some images. Suddenly Shepard, who's story has been about what a great leader he/she is, is completely alone in the world. Not only that we get no closure to THEIR stories. Dragon Age Origin's ending "slides" might not have been the most interesting thing in the world, but they worked wonderfully because they gave us a sense of closure to some of the storylines.
Personally I hope this is a knee-jerk from Bioware reacting to the "leaked" ending, and that down the line they intend to add some DLC. However if it's not Free I am fairly sure this would be the final rusty nail in the coffin of my Bioware fandom. This isn't a matter of me expecting free content, I am expecting a story of the level of quality Bioware has delivered in the past and they did not give me that. Their name carries with it an implied assurance of story quality and they did not grant that. Mix that with Dragon Age 2's dismal storyline and I find myself questioning my belief in them. The rest of the Mass Effect 3 story...well it would be like a cake in which the very bottom layer was something you hate with a passion. Sure the cake was delicious but the moment that last taste hit your mouth, what do you think is going to stick out in your memory?
For further reading, here are some well summed up posts of dislike by Azuriel and Rohan.
PS: The beginning was a little strange as well, but unlike the end, it's not the last thing in your thoughts. A relationship that starts off with a bad moment but goes on to be fantastic is not the one someone is going to remember negatively.