I will say this right of the back, the improvements in the graphic and battle departments are astounding. Which Dragon Age: Origins reminded me of the old school rpgs the graphics at times were stiff and the battles tended to get tiresome and repetitive after a time. If you were a warrior you could do well by pressing the same combination of buttons over and over again and manage to kill almost anything.
Where as with the new battle system you actually have to think ahead and take into account the cool down times of every ability you use. Though pressing the A button over and over again tended to get a bit tiresome as well.
However what I don't approve of is the limited area covered and the fact the basically copied the same cave systems over and over again. A cave system on the wounded coast was exactly the same as a cave system in Sundermount and going through them over and over took a bit of the fun out of the various side quests. Not to mention I pretty much had the entire map of Kirkwall memorized by the end of the second year.
I also didn't care much for the party interaction. The only time you could really speak to party members was during their companion quests and it seemed then the conversations were predictable regardless of which option you choose, short of flirting.
Other then that it is a fun game that you'd likely want to play over and over again despite knowing exactly what's going to happen every single time after the first play through. It is quite a bit shorter then Dragon Age: Origins which makes the replayability wear out quickly if you don't take a break every now and again.
Note that this game is very different from DA:O. You have to take it as a different game, otherwise you'll be thoroughly disappointed.
This game is just about one person, the Champion of Kirkwall. It plays almost for the entire game in one city, Kirkwall. And the story is completely linear, with your choices not making much of a difference.
Despite all these differences to what made the original game great (exploring a huge continent, while history was taking place and playing a pivotal role in events, making a real difference in the outcome), this game is a well-executed action-adventure all in itself.
There are games with much better graphics (Two worlds II has impressive environments, for instance), but it has a tight control scheme, good character models and is a fun dungeon crawler.