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. 
 

" AC2 was made by Ubisoft, not EA. "

I don't think that developers should hold back on ideas to include in their games. if they have things they want to put in they should. when AC3 comes out i'm sure there will be new things, evolved things, and they'll probably remove things. 
Suppose they decided to hold back on the villa stuff for the next game. there wouldn't be evolution of an idea from game to game. if they do decide to do something like the villa in AC3 then you know already what works and what doesn't. 
 
If/When they do modern warfare 3 you can bet that they will still find a way to up the ante. don't doubt the developers talents, they (generally) know what they're doing

there are a lot of things that never change.  am i the only one who is tired of sequel games? i want to see new ideas of games.

I'd say that the Nintendo school of "one addition every 5 iterations in this 25 year old series" is exactly what we need less of. I'd rather have too much new content and too many new ideas than too few.

Don't worry!  Assassin's Creed 3 will be very different from the second one, as the background will completly change, changing with it, what you can do within the game environment.  
 
But i agree with you, about that "this" effect. I feel that about games like GTA, Dragon Age, even Mass Effect. They don't seem to really change in any significant direction, other than size. The gameplay and possibilities feel the same. 

Nice post. Totally disagree in a way - I think the changes with Assassin's Creed 2 were exactly what was needed to enthuse the gaming public. A wider range of sub-quests, that all filtered into the main one, and the addition of a 'home' area with upgrades etc. And it's been proven by the much less divided critical praise that the sequel has received.
 
I also think it's weird to criticise any game for being 'overloaded'. Why should we be worried about the 'space for features in a sequel'? I couldn't care less if AC3 is less of a game because the second one was so good.

" AC2 was made by Ubisoft, not EA. "