So I beat Mass Effect 2 the other today. And all I have to say is WOW. Cheers for Bioware as they have produced another stunning product. There are NO spoilers in this article. All information is disclose about plot was for the most part known about before the game came out First let us go over the changes from Mass Effect 1.
So there have been so significant changes for ME2. First off, there is no more health bar from ME1. Your health is more like modern shooters, where the screen goes red if you loose your shields. Your squad has the same with a small bar next to their name representing health. Your squad has less powers this game, each member not being a class but more personalized with about three powers. This allows you to mix your squad more and not be so attached to a certain group. Your armor has changed as well. You don't buy new sets, instead you buy parts and can mix and match them at will. Each gives certain bonuses allowing you to create your own armor suiting your needs, no pun intended. In the first game credits were hard to come buy and you mostly had to sell stuff to get what you wanted. In this game, you get creds for completing a mission and there are many things to buy. They have added a new weapon, submachine guns, which are amazing at taking down shields. All this has really shaped Mass Effect into an amazing combat experience that is very simple to control. I would compare the combat to a game like Gears of War. Overall this has made the game much more enjoyable.

The story is remarkable. I highly recommend importing your character from ME1 because you get some bonuses as well as carrying over talents you maxed out. For example if you maxed out your charm ability, that carries over into ME2 with no need to upgrade it anymore. All character that you killed in the first game are dead, and there is no way to bring them back. This really makes you consider how you played the first game as it has a HUGE impact on ME2. People will recognize you and update you on things that you did in ME1. This all just adds to a story that is full of decisions and plot. Most of the story is you building your team, then going on a suicide mission. Build your team carefully and try to gain the loyalty of those who you really like. This will affect what happens in the end game. Overall this game is amazing, and really sets up an amazing finish for ME3, if you enjoy RPG's or liked the first one, you NEED this game.