First off, I’m not a huge fan of the one of three choices Shepard has to make to conclude the game. As a long time Mass Effect fan I was disappointed with the way the story ended. Not because he dies in 2 of the 3 scenarios but why the mass effect relays had to be destroyed. My major problem with the ending was this “epic” final battle that fell way short.
I was disappointed with the battle sequences at the end of the game. Let's just say for the sake of argument that you've been living under a rock and didn't play ME1 or ME2. You spend the whole game obtaining "War Assets" which are supposed to help you for the final battle against the Reapers. Most of the assets you obtain through the game are space fleets from different species. I don't know about everyone else but the short little space battle at the end didn't do all your work justice. Not by a long shot.
Then, when the Alliance brings in the Crucible they just stroll right in to the Citadel. Not a Reaper in sight. I mean what the hell? I just spent 30+ hours gathering all these assets and I got a maybe 2 minute space battle? All they did was run interference while the Normandy tries to get to London. I wouldn’t have been so upset with the ending if the battles had been better. I just felt like the final conclusion to the series was in no way as good as it could have been.