DA2 gets a bad rep, but considering that it had a development cycle of a year-and-a-half, when the "minimum" development time is usually two years for any major game of similar scope...
- It has a fully-voiced protagonist, which can be male or female, with any one of three different personality types (that's a lot of lines)
- The protagonist can be one of three different classes, which in turn determines who one of your companions will be and determines more dialogue
- Each class has three possible specializations, so different attack animations, effects, numbers, and algorithms need to be there
- Has to balance innumerable variables (i.e. plot decisions) from a previous game, thus providing continuity
- Has a dual-balanced morality system that determines possible dialogue with companions/NPC's on multiple levels (that's a whole lot more lines)
- I could go on...
Sure, the re-use of environments isn't it's strong point, but when you realize the context, it's a lot more understandable. Especially when you find out that Kirkwall is essentially built over a Tevinter blood-magic nexus/slave prison, and was designed to be drab and confusing so as to discourage revolt.
And anyone can make a "Good/Evil" morality system, and there's nothing wrong with that, it's a classic. But turning that expectation on it's head by adding a THIRD (snarky) while allowing for overall tone of voice to reflect whichever personality your character takes requires commitment and skill.
Not only that, but the Friendship/Rivalry system requires a lot more finesse than simply "Don't steal that person's money!" or "Give me his money and then I'll kill you!"
Point being, this game was made on the equivalent of a shoe-string budget with practically no time to do it, but they managed to create ALL OF THIS AND MORE.
It really puts it in perspective.