I'm just going to quote on the game finale. So more spoilers below.

"There's already multiple articles detailing why the fans are angry about ME3's ending, so I won't go over the plot holes (Normandy in the middle of nowhere, your chosen squad emerging from the ship), the insulting pop-up at the end (wasn't that touching? now for some DLC!) or the fact that I say "ending" rather than "endings" because the three options are little more than a palette-swap.

No, there's bigger problems with the ending.

Like how you spend the game making difficult decisions and sacrificing friends - and sometimes entire races - for the purpose of amassing the largest army possible to fight the Reapers. Oh yeah, and all those annoying fetch quests. Must fetch that ancient relic to encourage the Batarians. (Why? They're already out of the fight.) Must fortify the Citadel. What's that? The Citadel got invaded by Cerberus? What's that? The Citadel got KIDNAPPED TO EARTH?

Oh, but surely all the effort and sacrifice will be worth it in the end, when it culminates in a long series of battles against the Reapers, Shepard having a say in the strategic deployment of the different alien forces, just as he/she had a say in the pivotal decisions of ME2. Remember the ME2 suicide mission? That was some epic shit. Surely ME3 will amplify on that to a galactic level.

But no. In the end, all of that doesn't matter. It doesn't even matter if you've carefully sculpted your Shepard, one conversation at a time, as a hippy or a hardened grunt. Those bits that gave you Reputation +2? Doesn't matter. Effective military strength? Who cares. Agonising over the fate of the krogan or quarians? Don't bother. It doesn't make any difference.

Not only does your strength not matter, the enemy also doesn't matter.

If the origin of the Reapers had not been explained at all, that would have left a better sense of mystery. They would still be this vast, unknown, terrifying force of the universe, even as the story ended. And Shepard - or the Council if Shepard dies - would give a speech to the tune of, "we will never know where they came from, or why they did what they did. But we stood up to them, and we pushed them back. We gave it our all. The Reapers sought to break us, but instead we stand more united than ever."

Instead - in the very last minutes of the game - we are introduced to some kind of mystical AI who gives you the big picture. Because organics were creating synthetics and synthetics were destroying organics, it created the synthetic Reapers to prune the organics. Wait, what? To prevent synthetics from destroying organics, it created synthetics that destroy organics. Except, you know, only every 50,000 years, and only the advanced races. That's the dumbest artificial intelligence ever.

Why add this shoddy extra layer, right at the end? It's better to offer no explanation at all than to give us this recursive nonsense. On top of that, the Reapers are suddenly demoted to a bunch of henchmen. They're not scary anymore. Their mystique is gone. Harbinger is a puppet.

I didn't want a happy ending. It was impossible anyway, with the odds the galaxy is facing in ME3. Shepard would likely die. That was fine with me. I would have even liked a hopelessly grim ending, with everybody failing and the Reapers continuing their unstoppable advance.

Instead I got deus ex machina, Adam and Eve, and a bucket of cheese."

Oh, and I'm not angry. Just very disappointed.