I really enjoyed the game, overall. It's not without it's quirks, mechanically, but overall I had a lot of fun playing a two-handed warrior and beating the daylights out of just about anyone that tried to stand in front of me. I tried the rogue for afterwards, and I found the combat style much less interesting and engaging, even though I could tell there were powerful attacks involved. This continues the trend from Origins, where I think I got the play style I liked the best on the first try, which is nice.
Now, the plot. I really liked the plot up until the 3rd chapter. In the earlier parts of the game, there are circumstances where you may not understand what is going on, but it's because you're tossed into difficult situations with insufficient information, which might be called a neat summary of the idea of an "adventure". However, in the 3rd act the game abandons all complexity in the name of having you choose between templars and mages. That frustrated me to no end, because I never felt circumstances were such that a simple choice made sense. Even in the final quest, there is are several immediately obvious solutions to the crisis that the game refuses to acknowledge. Also, I got in the back for taking the choice I did. I picked the mages, and then got to watch basically every mage that wasn't in my party turn to demons and/or blood magic. Though maybe I should have seen that coming, given that I now can't recall too many mages throughout the game that managed to stay on the straight and narrow.
The ending, basically, sent me through an abbreviated version of the Kubler-Ross Model of grief. It's such a terrible ending to such a great game. There's no closure, there's not a sense that most of what you've done up to that point even mattered. And, in my case at least, there's no sense that the big sequel-relevant choice I made was what I actually wanted. I've seriously contemplated playing most or all of the way through again just to see if there is a better way, but I'm starting to have serious doubts. The inability to bargain at critical parts of the 3rd act probably will continue to prevent me from having the effect I think I should be able to.
Of course, I'm also hooked. I can't say that this is seriously going to stop me from buying an expansion, or even the DLC when it's released. I do love Dragon Age, even if this one was kind of a downer.
On smaller points, I did like the "long-term" approach to the game, but I also don't think it was implemented as well as it could have been. One of the high points in the game for me is a simple conversation with Varric, where he asks Hawke what he/she will do once they have "made it" after the Deep Roads expedition. There are several options, and each of them hint at a life after adventure. It was interesting to think about, even though I knew that none of them were likely to happen. But it certainly seems that the characters should be thinking, and talking, about it. Surely some, or most, of them have aspirations beyond "kill the biggest dragon I can find" and/or "get filthy rich". It would be nice to sometimes see PCs, as well as NPCs, express those sentiments.
I'm running out of time, so I'll just say that I did enjoy the game and don't regret the purchase, even though the end was a downer.