So I was playing Assassin's Creed II and remember hearing the main story line will be a trilogy, that game has to much stuff to do in it. Your not just an Assassin, your a avaitor, investor, historain dude, and many many other things. There's going to be a challenge when it comes to adding more features to the next one. What I'm saying this series grew up waaay to fast, there's no room to expand the series. I also saw this in Modern Warfare 2 and GTA IV after all the DLC. 
   
              I can't think of name for this effect, but I'll edit it in as soon as I can. This overloading of games happens for one reason: not thinking straight. People will always buy Assassin's Creed games, Call of Duty and GTA games, let the series evolve over time. The most noticable one is hands down Modern Warfare 2, what else could they put in that game to expand it, not make it better exactly,but to expand it. Sequels are created to expand a game and improve upon the last titles faults, don't overload it with stupid amounts of stuff. 
 
              The game I think did the best of avoiding this was Pokemon. Look at the changes over time. In Red the craziest feature was riding a bike, that blew my mind! Then in Saphire you were making forts and stuff and in the next generation there a Pokemeter or whatever it's called, that's how you evolve a game. Game devs need to take there time wre creating a series that they know will be popular over time.  
  
 Edit: Sorry for typos I was rushed off the computer.