You made me cry BioWare... for good and bad.
Combat feel about the same as Mass Effect 2, but powers didn't feel as much fun to use (playing as a Soldier). Enemy variety also feels worse compared to the earlier games, there are reaper infantry and Cerberus... and that's pretty much it. Oh, and there are turret sections. All in all, the gameplay feels a lot more like Gears of War compared to the earlier games.
Dialogue choices are dumbed down, there is only paragon or renegade choices, no middle ground. Quite disappointing.
As for the ending, I didn't hate it as much as I feared I would. In fact, I cried to it because of how emotionally powerful and sad it was. And I would have been okay with that.
However, it's when you think the ending through that you likely will get really disappointed. It just doesn't make any sense, gives no closure, is a rip-off from Deus Ex and basically ends in a cliffhanger.
So the ending brings it down from a 9.0 to an 8.5, as the rest of the game is mostly great, despite it being more casualized with even less RPG-elements than Mass Effect 2.
This game really made me feel something, even though I am torn about the ending. I don't need it to be a happy one. I just want it to make sense.