Finally got a chance to play the game. Minus a few issues here and there that I have, I really, really liked this game. I do think it lacks some of the magic and fun that the Rocksteady games had (the attention to detail, freshness, and "wow" comic book feel are either gone or watered down to an extent) but it is still a solid entry, still holds up to the Rocksteady games overall and is worthy of the Arkham title IMO. For a game that was essentially just an appetizer until the real "Arkham 3" comes out, I feel it achieved a few things that made it much more than just an appetizer.
Since it is very late where I live and it seems most of the positives of the game have already been addressed and discussed many times since the game came out (based on the pages I skimmed over), I'll mainly just address the negatives for now.
This game went out of its way to make my two biggest fears come true: Joker's origin and the "empty world syndrome".
I never got why some writers would decide to go the (somewhat anticlimactic) Red Hood route and establish Joker's origin as fact as opposed to the more Modern Age/Killing Joke approach of his origin being a mystery (other than the fact that Batman had some sort of involvement in his creation) and him always interpreting it in a different way. On top of that, it doesn't even make sense continuity-wise because Arkham City
did go the Killing Joke route and establish his origin as a mystery (listen to the interview tapes). Sure they don't directly come out and say it's his actual origin and it could have been just the origin the Joker remembered on that day, but they still heavily imply it and that bugs me.
As for the "empty world syndrome", although nowhere as bad as in the Spider-Man games, it is still a problem here nonetheless and it's disappointing to see the franchise get hit with this syndrome after avoiding it thus far. Rocksteady knew they couldn't do a full-on Gotham game justice so they stuck to the "less is more" approach and created two incredibly detailed maps with tons to explore. Origins sacrifices that for a bigger map and even takes away some of the magic and fun away in the process.
It also has some continuity issues.
Certain things in AA/AC are contradicted. How does Batman have the grapnel boost? Why isn't the new detective mode built into his later masks? Why did he go around carrying a huge gun in AC to shoot electric things if he could just use gloves? Harley's first meeting with the Joker doesn't match their first meeting in the AA tapes. It is also completely impossible for this to take place just 5 years before AA.
Then there are certain parts that have prequelitis. The biggest example is Bane. They did such a fantastic job with Bane (easily the best adaptation of Bane IMO) only to turn him into a brainless moron by the end due to him being just that later on.
As a side note, it was a great idea to wait until the Christmas season to play this game. Nothing fit the mood better than playing the game with Christmas decorations around the chimney (next to the TV) and the Christmas tree next to me.

t: