Not many people bought the original Dead Space game, which is a shame as it easily knocked Resident Evil off it's pedastal with it's brilliant mix of horror and action. Dead Space 2 expands on this and more. This is the perfect game for horror fans!
It takes place 3 years after the first game on a gigantic spacestation called 'The Sprawl'. The alien necromorphs have once again attacked and it's up to Isaac Clarke to stop them. However, Isaac is not only battling the aliens this time, he's also battling with himself- Isaac is now suffering from dementia following the events of the first game and frequently has hallucinations throughout the game. Needless to say, it all makes for an extremely disturbing experience.
I won't go into the storyline anymore, you really do need to experience it yourself, it's stunning. As for the gameplay itself, there's really nothing to complain about. Controlling Isaac feels even more fluid than it did in the first game, and he now has several new abilities and weapons up his sleeve. Remember the kinesis ability from Dead Space? You can now use this to rip the limbs from dead necromorphs and hurl them at your enemies, impaling them. It certainly helps to save ammo, especially on the higher difficulties!
While I'm on the subject of difficulty, it should be noted that in order to have the perfect Dead Space experience, you should first play through on Survivalist mode. There are four difficulties- casual, normal, survivalist and zealot. Plus, once you finish the game, you unlock hardcore mode. I'll let you find out for yourselves what that's like. It seems normal difficulty has been toned down a bit this time round, to allow for more accessibilty, but you really need to start the game on survivalist mode, otherwise the scares simply won't have the same effect.
All in all, this is an amazing game. If you enjoyed the first one, it should be a no-brainer. Pick this up! Even if you didn't play the first game, there is an introductory film to let you catch up on the events of Dead Space. There is simply no excuse not to buy it. One word of warning though- you may develop a slight fear of needles after finishing it...