I'm not going to get into any of the story details to avoid any spoilers, but i will say that Mass Effect 2 continues from where the first game left off pretty good. The only problem and one of this games major problems is that there is not much of it! What do i mean? Mass Effect 2 sure as hell is not short, it's actually bigger than the first game, but you spend most of the time recruiting people for your team and helping each and one of them with their problems. Every single person you recruit has a problem they need fixed.. and you commander Shepard are the problem solver. Its cool a game like this has some side missions to do here and there, but when most of the game is like i said recruiting and helping with their problems you start to think there is not much of the main story.
Remember the uncharted worlds in Mass Effect 1? They sure looked plain... mountains and more mountains. Well at least you could drive the Mako all over them... that was a bit fun. Now instead of doing that we do planet scans in the Normandy. It gets a bit boring after a while... and you need a good amount of minerals to research new weapon upgrades so there is no choice but to scan... probe away.
Negative things aside Mass Effect 2 improves on the first game in many areas. Graphics are now a tiny bit better, they look more clear and no more frame rate drops like the first game.
Gameplay has improved in a number of ways. Now you can take cover and even jump over cover. When you shoot at an enemy you can actually see him move when he is getting hit. Guns no longer overheat. Gameplay is not Mass Effect's biggest strength, but overall an improvement from the first game.
Mass Effect is by far the best series on 360. ME2 is a great game, just not as good as the first one even if it has some improvements in some areas. Story is the most important thing in ME, and that is where ME2 fell the most. I hope ME3 is better. Bring on the Reapers!
DLC: Before i end my review i also wanna say DLC is disgusting and it shows in Mass Effect along with other games. Day 1 free DLC with Cerberus code? Free? Yeah right! This DLC should of already been in the 2 disc's. Bioware even had future DLC planned that's why there was always an empty space for a new DLC character. I can live with some extra DLC missions on some uncharted worlds or some new weapons and armor... but new story characters? Milk Milk Milk.