Mass Effect is the best game on the 360. it is simply wonderful and amazing.
Story: somehow, Bioware managed to create a better and more believable universe than the Star Wars EU, with only one game versus 30 odd years of material.
The story is really good. it twists, it surprises, it satisfies. it's delivered really well, the writing is excellent, and bits and pieces are revealed throughout: eg. you find out more or less the same thing in two missions you can do at the same time, in any order, but you have to do both to get the full picture and advance. extra, non essential, story is spread out through side missions in a way that makes you want to check everything.
Gameplay: there's a pretty sharp learning curve. it looks like it plays as a third person shooter, but you cannot forget for a moment that it is also an RPG. you can;t just run and gun it, you have to stop and think of what to do.
visuals: stunning. obviously not the best you will see on the 'box, but that's because there is simply so much to fit on one disc. the character models are the best i have ever seen..... some look photo-realistic. the animation is superb, lip-syncing great, and the movements of the characters look real, like a movie. this game really is a cinematic experience.
a few downsides though.... it uses the Unreal 3 Engine.... and that means texture pops. it generally happens in one section of the end game, or when you are in the airlock of the ship. they do look yucky, because they are such a clash with the rest of the game. but if it is only one layer down on the graphics, it is the kind of textures we'd have accepted a few years ago as standard.
character creation is a delight. forget oblivion, you can make a male or female shepard that looks really cool and unique.
sound: the acting is good. very good. every character is a stand out. and Seth Green is the pilot, he fits really well. he's underused, but he's really good. if you played KotOR, you'll also recognise the voice of Kaidan as the same guy who did Carth.
this game is, overall, brilliant. it's not often you get to say it, but Mass Effect is one my list of all-time best games i have everr played, up there real high. i lost myself in it for hours...... i played 22 hrs before i started the main quest, and to date, i have played 80-90 hours.
that's two playthroughs....... and i will need at least two more.
seriously, try this game. don't rent it, buy it, or borrow it from a friend. or at least rent it to help your decision to buy it.
you will not be disappointed.
GOTY, for sure. i'd give it 9.75, but i'm not allowed to.