Coll Regan                               Sequels don't have to be bigger
http://www.escapistmagazine.com/articles/view/columns/extra-punctuation/9999-Its-About-Characters-Stupid

    Whenever you hear the term sequel these days you think Aliens, how it changed from a small, quiet, creepy ship into a huge action movie with lots of explosions, gunfire and death. In a way Aliens has changed how sequels work and not necessarily for the better.  These day whenever a second instalment of a franchise is made its almost always bigger and more, and this normally ruins the original feel of the series and changes it into something else entirely. Dead space is the perfect example of this, in the first one your just in a deserted(not really) ship that is relatively small and the game has a pretty narrow scope. These factors made the game one of the best survival horrors ever made, but with the second one they completely destroyed that tone. Don't get me wrong, it's still a great game, but they plonked you down in the middle of a huge city amidst chaos with people running everywhere and explosions a constant. They then proceeded to give you tons of ammo and threw crazy amounts of enemies at you, and it changed the whole series, it left the creepy survival and became an Aliens style action game where you mowed down anything and everything.
    To make a second game in a series it doesn't have to become so big and explosive, they can stay small. I mean the games can still become bigger, but instead the focus should be less about having bigger action, but more about the characters. All the better parts in any sequel are when the characters show how they have changed and become different people, such as Isaac throughout the dead space series. When a game goes huge and has something to do with world domination or large consequences it's hard for any type of continuation after that as it's challenging to go much larger in scope and this therefore makes anything after it less impacting as odds are its going to be something much similar to it.  The thing is as long as they try to focus on characters in addition to the crazy new gameplay they implement it would help to keep any game in its roots but at the same time becoming greater than what it originally was, although the tone of the game still may change. In the end if developers want to keep sequels in the same image as the originals they are going to have to not always think about going bigger but just deeper into the subject matter.