Epic science fiction tales at their finest
The story is pretty well-written, and to me, it seemed to be adequately wondrous and science-fiction-like enough. Even when the main plot is relatively simple and ordinary, it made me think about stuff and think about the characters - this is always a good sign. I also appreciate the fact that the game is definitely more of a "science-fiction" game than a "space opera" game; the designers put a lot of effort into writing a backstory and a bunch of technobabble that sounds plausible and well-thought-out. It's not just "it's got spaceship and ray-guns in it".
Graphics and music are top-notch, and the character art and animation is very good. Voice acting never really gets jarring, dialogue works surprisingly well.
This game is also one of the few games I really wanted to pick up for a second playthrough almost immediately afterwards. The game is not too long, yet not too short either.
The planets you can land on are quite fun to explore, and the sidequest missions are interesting enough, but the problem is that the planets are rather bland and the sidequests are set in The Mine or The Base or The Other Kind of Base or The Spaceship - there's literally one map for each submission, with the interior objects slightly changed. This doesn't allow for much variation, and you can pretty much figure out a single strategy for them and then just say "Okay, now we're raiding The Base, here's my tried-and-true plan".
The firefights are chaotic to say the least. The enemies have absolutely no strategy, and they just run around a lot, usually scurrying around just as you're about to aim at them. This is compounded by the fact that your squadmates have no strategy either, and when these enemies scurry out of your line of fire, your squadmates offer to put their heads on the line of fire, instead, just as you pull the trigger.
Some of the game mechanics remain obscure. I was half-way through the game until I finally "got" some of the subtleties of the game - and could have played through without really getting them.
Yet, none of this is all that big. Even when blandness sometimes shows, the main plot definitely makes up for it.
The Bottom Line
Welcome to an epic science-fiction tale where the humanity has uncovered mysterious alien technology to allow faster-than-light jumping around the galaxy, and met several interesting alien species. Humankind is just about to be admitted to the greater galactic bureaucracy as one of the prominent races. And we, on the other hand, have to go examine the exploits of the crew of humanity's most advanced spaceship. The first call is to examine a rather mysterious conflict that is quickly unfolding in a rather sleepy planet; this immediately leads to the trail of a new threat to all sentient organic races.
The humankind, of course, does what it does best, as far as fiction is to be believed: kicking butt. Mass Effect is a tactical third-person shooter... and a RPG... and you get to drive around in an APC too... oh, and you have a starship and you get to conduct some exploration too. Dialogue is a heavy part of the game: situations can be often solved with guns or through eloquent or threatening speech. The character is given choice between acting nicely and heroically ("Paragon"), or just getting the job done no matter what it takes ("Renegade"). Not really a good vs. evil system, but close. These choices award points which are tracked independently; the better you are at either, you also get the chance to be more persuasive or intimidating.
The player controls a squad of up to three people; each character has unique talents and strengths. The player character, Shepard, can be customised as well. At your disposal you have a bunch of different weapons (grenades, assault rifles, pistols, shotguns and sniper rifles) that come in different makes and models and can be customised with various kinds of mods. Different character types can use different weapons to their advantage. When the characters level up, they learn new powers. Aside of conventional weaponry, there's a bunch of biotic powers that are extremely handy. When you land on planets, you also have at your disposal an armoured vehicle, called Mako, that has the necessary big guns.
In short, Mass Effect is a really well-done science fiction RPG, with only minor flaws that don't really take away too much from fun. It has tons of engaging dialogue, has a well-crafted milieu, and enough interesting plot twists to keep you busy.