The story contains suggestive violent, betrayal and adbuction themes.
The story will make sense if you have played the first Mass Effect. So either play it or consult an appropriate Wikipedia article to know what exactly happened in the first Mass Effect.
The Mass Effect 2 begins right after the story of Mass Effect 1 ends. Normandy, a powerful and agile spacecraft belonging to its captain, Shepard (the protagonist) is lurking around to find the Geths. But a big unknown ship shows up and destroys the Normandy badly. Shepard and Joker (pilot of the Normandy) manage to get to the escape pods but are separated due to some circumstances. Almost all of the members aboard die. Shepard interestingly survives and finds himself awake being operated upon in a lab by one of his squad mates. He later comes to know that he is in a multi-billion dollar organization, Cerberus.
When he wakes up, he is summoned by the Illusive Man, head of the Cerberus. The Illusive Man tells Shepard that the entire human colony is being continuously wiped out and believes that Reapers are responsible for this. He also believes that the Reapers are not killing humans directly, rather they are getting the deed done by another deadly species, the Collectors. Illusive Man wants Shepard to basically end this all but warns him that for doing so, he will have to pass through an Omega-4 Relay, from which no ship has ever returned yet! He manages to convince Shepard to visit a recently attacked human colony and gather anything valuable. He appoints Jacob Taylor and Miranda Lawson as his new teammates and tell him about the newly constructed and even better Normandy.
Shepard rejoices to see a new Normandy, which now has been renamed as the Normandy SR-2. It has improved weapons and defense system. It is also now fitted with an advanced AI computer called EDI. On some side missions, Shepard adds four new teammates into his crew and receives new orders from the Illusive Man to visit another recently vanished human colony. Shepard manages to save the colony but a large number of it is already captured. Shepard leant that Collectors are actually Protheans but were made slaves of Reapers later.
With the help of EDI, Shepard figures out a way to enter Omega-4 Relay without drawing any attention. Shepard by this time has gained enough trust from all his crew members and he grabs an IFF transponder from a Reaper. This transponder is necessary for a safe travel from the Omega-4 Relay. When reached, the crew is captured by the Collectors. Joker is the only one who manages to flee the capture.
After a tough exertion and a healthy dose of luck, the crew makes its way inside the Collector base. He witnesses a shocking fact that the Collectors are actually making a new Reaper race from the abducted humans. Shepard's final battle is with a human reaper who controls a big robot kind of thing. Shepard destroys him and prepares to flee as he was all ready to blow the Collector base apart. On the final moment, Illusive Man suggests taking the Collector technology while escaping so that the Collectors could taste their own bitter medicine. The bomb detonates and the crew manages to escape and becomes the first ship to make out of the Omega-4 Relay. Illusive Man congratulates him and the entire crew. Some crew members die in the journey and some are badly injured but they all manage to stop further abduction of the human race.
In the end, a Reaper fleet is seen awakening in the dark space marking the beginning of Mass Effect 3.
Ever had a feeling that you just don’t want to do a thing but there's something that keeps pulling you into it? To be straight here, it’s the game. It’s lengthy and its story is just great. Leaving all good factors aside, let’s assume that there is a factor XYZ in this game that just won't let you turn your computer/console off until you finish the game.
We shall get to define this factor XYZ now, shall we?
Maybe, it’s the outstanding story. To read this story is like reading any other boring story, making no sense. But when you actually play this game, you will realize that part after parts, this story becomes better and just better. The story is just addictive. There is part in every incident that will leave you wondering about what's going to happen next. To accomplish this, you will play this game until you realize that its already night and you had started playing this from the morning.
Maybe, it’s the tremendous amount of playability and control over the story. Throughout the journey, you as Shepard make many friends and teammates. Almost all teammates belong to other races and they simply don’t have trust in you. They all are either betrayed, abandoned or seek to accomplish something. Its 100% up to you whether you want to gain their trust or not. Gaining their trust means that they actually fight for you and that they will not turn up on you. Also, the crew that places trust on you will have some special power which you will not regret fighting for at the very right moment against the Collectors. It all makes you control the very story all by yourself. The basic plot will remain the same, but the story will change many instances which you may regret or enjoy. You can play a hero or an evil while talking to a person. If you play a hero and help a person, you gain his/her faith and maybe a few upgrades for your crew. If you play evil, you will save yourself time for going on a mission to kill thousands of ememies and retrieving a cat but you will lose faith and trust which can later turn up on you at just the wrong moment and make it worse.
Maybe, it’s the awesome gameplay. The way you take cover, and take down your enemies. The way you can unleash special powers upon your enemy and leave them good for nothing. The way you can command your crew to do exactly as you say. It’s all amazing. You can upgrade your weapons and the defense system of Normandy by visiting different places. You can collect different elements from different planets and use them for upgrades that you will not regret at all. You will also need these elements to construct a few things as the story will unfold.
Maybe, it’s the technically great graphics and commendable voice acting and audio sounds. At any time in the game, the story and the incidents just feel alive. You become a part of the story. Especially when the graphics are cranked up to the maximum and you are playing this game on a Full HD monitor, and you have a nice pair of headphones, it will all add up to the beauty of the game.
Maybe, its characters of the story and the variety in the game. When you progress your way up the story, you will make many friends. All specialize in something special, some in power, some in strength, some in disguise and some as a great support to be around you in everything. You decide which characters you need in your missions. But in the end, when all characters come to play, it will come forth their loyalty and trust in you. If you helped them, they will help you in the final mission. If you don't things the other way around.
Or maybe, it’s a healthy combination of all these possibilities. The factor XYZ is no longer unknown. I have very much described this factor XYZ in this review. It will keep you glued to the screen until the credits roll and make you beg for wanting to play Mass Effect 3. This game is simply awesome. You must play it if you haven't yet.