Assassin's Creed Revelations is a quality game, but it is not up to the standards set by previous installments.  Once again, the freeflow combat is smooth and responsive, yet still fairly repetitive.  Once again the audio is top notch, with great music and voice acting.  Once again, the tombs and multiplayer are well done.  However, the story (the main reason I think most are hooked on this game, including me) is lacking.  There is very little in the form of continuing the story, as we only learn about past events, in the form of multiplayer Abstergo information or Desmond's life in the Portal-esque challenges or flashbacks to Altair's life.  It is pretty obvious that Ubisoft is setting up their big release for 2012 in Assassin's Creed III, as all information and story gathered in Revelations is meant to set up for some big event/"revelation," which does not come this game due to the cliffhanger ending.  It seems like someone could have skipped Revelations and still been up to date with the current story for ACIII.

There are some gameplay errors with Revelations.  The tower-defense style den defense is sloppy and annoying, and the only way to stop it from happening is to keep the notoriety down.  Worrying about notoriety gets annoying because you cannot do many fun or amzing things without sticking out and raising the notoriety.  It was a terrible idea and it was badly executed.  The chariot battles were also badly done and fairly annoying as well, where you just have to bump into the other chariot harder.

That said, Revelations did most of what the series is known for well.  Even though it is just background, the story is interesting, especially Altair's flashbacks.  Good combat and audio like I said before also buoy this game.  Though the game is a seat-saver for ACIII in 2012, it is a darn good seat-saver.