Dead Space 2

The original Dead Space was a grippingly tense sci-fi spin on the survival horror genre, yet it was only a modest hit, which is why many were worried about the prospect of a sequel. Logic and history dictates that any changes would only hurt the franchise, turning off longtime fans while failing to gain any new players. Instead the transformation between the first and second games was exploding with improvements for the series and made the original title seem lacking in retrospect.
The most important update was the added depth to protagonist Isaac Clarke. He went from silent cypher to a character with thoughts, feelings, motivations, and (of course) fears. His journey through the ruined city of The Sprawl is all about him coming to terms with happened to him in the first game, and you watch him grow and change as you simultaneously hack the limbs off hundreds of necromorphs. This welcome bit of character exploration was supported by brilliantly eerie levels like the day care, breathtaking set-pieces like the tram crash, and some of the grossest things that have ever happened to eyes in a game. Dead Space 2 not only proved the original wasn’t a fluke, but that it was just getting warmed up.