Game of the year. Already.
Now, about the events of the previous games: any decisions you made in the first game will carry on into this game. If you chose you kill a character in Mass Effect, they remain dead in Mass Effect 2. If you destroyed a race, they're still extinct. If you got onto the wrong side of someone, they're still going to hate you for it. Considering the countless choices you made in the first game, it's really quite impressive that everything you did carries over into this game. This game, however, is a much darker affair than its predecessor. Moments into the game, your ship the Normandy is attacked by an unknown enemy. The crew are sent to disparate parts of the galaxy and the game continues two years later. A mysterious alien race known as the Collectors have begun capturing human colonies across the galaxy for an unknown purpose. You have been hired by a shadowy organisation named Cerberus to investigate the abductions and bring an end to the Collectors. To do this, you are sent to assemble a team to assist you in your mission. Throughout the game you come across one of the finest ensemble of characters ever conceived in a video game. You will come across characters from the first game, as well as assassins, prisoners, scientists and criminals. The entire galaxy is yours for the taking as you choose whether to continue your characters do-gooding or reign of terror from the first game, or choose to totally change his appearance and personality. For those who have never played the first game, you can just create a name character and the game will play as it normally does, only without the decisions from the first game carrying over into this one. It's still hugely recommended that you play through the first game before this though, as they're both highly rewarding experiences.
In terms of gameplay, the game is superior to the vast majority of Third Person Shooters and Role Playing Games out there. The combat is as kinetic and pulse-pounding as anything you'll find in Uncharted or Gears Of War and the Role Playing elements are fleshed out just as much as in Fallout 3 or Oblivion. This game perfectly melds these two genres together, much better than any game has ever done before. In fact, the two genres have been mastered to such an extent that it is quite easily possible to just play the game as a Third Person Shooter, ignoring the Role Playing elements, and it could still be an all-out classic video game. Whether you want to go in all guns blazing or take a tactical approach to combat is all up to you. This is your game, you play it any way that you want to play it. It's all up to you, as the player, to decide how the story, character development and the gameplay progresses. The sheer amount of detail put not only into the gameplay, but in the story and overall universe of the game is astounding and incredible. This game is truly the next step in action and storytelling within video games, with immense set pieces, sprawling environments, countless side-quests, endless outcomes in missions and infinite replay value. Mass Effect 2 is quite simply one of the greatest video games ever made and if a better game is going to come in 2010, it's going to have to put up one hell of a fight to beat out this. If you own an Xbox 360 or a PC capable enough of playing this game, you absolutely need to own it. If you don't, you're missing out on a landmark in video gaming. Well and truly the most essential Role Playing Game in the past decade.