I have both positive and negatives. I also enjoyed it a lot and loved the ending, but here are some things that could be lacking, on top of the average gameplay.
The game presents you with a living city, unlike Bioshock 1, but your ways of interacting with the world are basically as just as limited as in Bioshock 1, it hasn't advanced at all. The game is at its most immersive if you try to roleplay the character and run through the areas as Booker would. If you try to explore everything and inhabit the world, there's very little to do and interact with... but on the flip side, a ton of story content – like Booker possibly being partly native american, being white-passing and self-hating – only comes from voxophones you get if you thoroughly explore the environment. Not exactly a drawback, it's the same as Bioshock 1, but you might expect some advancement in the decade between them. And in Bioshock 1 there's a good narrative reason to only be able to interact with npcs by fighting.
The e3 gameplay demos showed more open-ended areas and much more creativity in how Elizabeth used tears. In the actual gameplay you just use them for turrets, ammo, hooks. The scope got reined in (understandable).
Not the greatest/most progressive narrative on race/oppression. It makes sure to accurately portray the racism of the time in a lot of the beginning, and you and Elizabeth sympathize with the poor as you travel through the poor districts and fight Fink. However, after the uprising, Elizabeth's takeaway is pretty much 'wow, both sides are awful,' and the game stops talking about it, it's not important to the 2nd half of the game. Could be totally realistic for Elizabeth's and Booker's characters, but it's not necessarily going to be popular or resonate with audiences. There's also no way to interact with or do anything about any of the racism (aside from 1 single moral choice point in the beginning, which has little gameplay impact), which again is fine if you're roleplaying as Booker's character, but others might not find fulfilling. On the flipside, they don't portray the sexism of the time, with female enemies like other modern games now have. If they were willing to make some things more progressive because a super sexist game would look bad, why make people play through old timey racism for no narrative payoff.
Doesn't do much with the historical setting. Religious cities at the time were big on alcohol prohibition, and Booker's an alcoholic. Would have been cool to see some interaction there, idk.