Combat is awful. It almost spoils what is otherwise a memorable experience.
I have frequently seen Mass Effect described as "Kotor with Biotics instead of the Force". This description is wrong in a lot of ways. The game has some of the obvious stamps Bioware's work, but it is a significantly different game. The first major difference is that the Mass Effect universe is almost nothing like Star Wars. The only thing that Mass Effect and Star Wars have in common is that people use energy weapons that make a "pew pew" sound. When it comes to aesthetics and atmosphere, they are completely different. Mass Effect contains a lot more science in its science fiction – so much that if you wish, you can visit the Horsehead Nebula and find out what kind of mineral deposits are on the planets orbiting obscure stars there. Visually, Mass Effect is much cleaner looking - almost eerily antiseptic - whereas Star Wars shows a dirty "lived-in" future, as George Lucas describes it. More significantly though, the Mass Effect universe is much heavier in cynical politics and darker in tone than Star Wars. In this regard, the storytelling in Mass Effect is more like what you would see from Joss Whedon than George Lucas. Mass Effect's aliens are almost all essentially humanoids wearing masks, which makes it more like Star Trek than Star Wars.
The fiction in Mass Effect is ultimately a major asset to the game. It appears on the surface to be unimaginative and derivative, but as you delve into it, you find all kinds of intrigue, background, and detail. There are about four or five critical races, and none of them trust each other or get along very well, making the universe a lot like the Balkans. Ancient atrocities linger in the present as bitter resentments. Politicians are frustratingly stubborn and bureaucratic, concerned more with image than about averting an intergalactic crisis. Corporations exploit lax intergalactic law enforcement to push ethical boundaries. Mass Effect is an adult-oriented game, not because of language or it's much publicized (and almost nonexistent) sexual content, but because of its mature themes and writing. It's a shame that Bioware did not craft a main storyline that matches the quality of the background. The central plot in the game is a stupefyingly mundane story about saving the universe from an ancient foe.
The role-playing system in Mass Effect is brand new, and it is another asset for the game. At a time when role playing games are becoming progressively neutered and simplistic, this game sticks with and old-school approach where you assign skill points to meaningful abilities when you gain levels. The skills allow you to improve defense, skill with guns, biotics (i.e. magic), hacking, buffs, and persuasion. The system is well balanced for something that is brand new, although hacking is a bit underpowered.
As you might expect from a Bioware RPG, Mass Effect is loaded with dialog. Much of it is the typical information gathering and questing that comes in any RPG – i.e. "tell me about your past" or "OK, I'll do this job". Refreshingly though, Mass Effect has many meaningful choices in the dialog, and those choices have obvious consequences later on. At least a couple of your companions can live or die, based upon choices that you make. Some of your choices will show up in news reports that you hear in the game's omnipresent elevators, while others show in dialog later in the game. The role-playing system has Charm and Intimidate skills, and both of them come in handy over and over again. If you have a high enough verbal skill at the end of the game, it is actually possible to avoid major combat with a boss. I can't recall a role-playing game off the top of my head that used persuasion skills in this manner.
Another of the game's greatest assets is its beautiful presentation. When it comes to character models, faces, and animations, it is the most stunning game ever made. Much has been said about how incredible conversations look in Mass Effect, and all of that praise is appropriate. The skins are incredibly detailed and armor is perfectly modeled so that it has depth and texture. The environments sport the same level of fidelity, although they are frequently bare, boring, and repetitive (copy-and-paste is one of Mass Effect's flaws).
The audio is even better than the visuals. The voiceovers are solid all around, headlined by recognizable actors like Keith David and Lance Henriksen. The most pleasant surprise in the game is the soundtrack. Rather than playing it safe and inserting a generic Jeremy Soule soundtrack into the game, Bioware chose a totally unique, synthesized score. It is low-key, but hauntingly beautiful at times. The music that plays at The Citadel (the game's first big area) is reminiscent of the music that plays at the opening of Blade Runner. The music that plays while you are looking at the galactic map matches the picture so perfectly that you might expect Carl Sagan to pop up next to you and wax poetic about the majesty of the universe.
The universe, the writing, choices, the lifelike characters, the music -- they ultimately allow the game to overcome its problems. Specifically, Mass Effect has one major problem. Combat. It is downright awful. Combat-wise, Mass Effect can best be described as "Rainbow Six Vegas with magical powers". When fighting begins, the game essentially becomes a squad-based third person tactical shooter. As such, it fails miserably.
In order to discuss why this game's combat is so bad, it helps to talk about what makes the combat in other squad-based games so good. In competent games like Freedom Fighters and Rainbow Six: Vegas, squad mates are an asset. They have solid AI that can use cover. They can stay alive by shooting nearby targets that represent the greatest risk. They can find a path around obstacles to the opposite side of the room without getting lost after twenty feet. Controls are competent and cover is easy to use. In addition, levels are designed so that you can slowly progress through them, advancing carefully and tactically. Enemies are also smart and can use cover, and your weapons are dangerous enough to keep them pinned to a spot, if necessary.
Mass Effect has none of these qualities. The combat in this game is a stunning example of poor design. First and foremost in this disaster is your squad mates' nonexistent AI. Your squad mates are astonishingly retarded and unable to perform some of the most basic and critical functions in the game. They are horrible at using cover. Sometimes, when you position them behind cover, they will stand out from it and get cut down. Other times, they will fruitlessly attempt to fire through the cover, as if it weren't there. Once, I stood and watched a hilarious fifteen second battle where an enemy and one of my mates stood on opposite sides of a box and continuously fired at each other -- straight into the box. Furthermore, your companions' pathfinding is abysmal. They frequently refuse orders to move to an easily accessible spot or fire on an enemy that they can't immediately see. They also do dimwitted things like cling to cover doing nothing while somebody runs in and shoots them in the face. This is the kind of atrocious AI that I would expect from a Valusoft game, not from a major developer like Bioware. Fortunately, the enemies are just as dumb, but they often make up for it with sheer numbers and brute force.
The problems with combat don't end with the AI, however. The controls are lacking a "cover" button, and the game is inconsistent when it comes to figuring out when you want to snap to cover. Kane and Lynch got skewered by reviewers for this flaw, even though its cover mechanic worked better than what is in this game. Why doesn't Mass Effect get reamed for this? The game is full of tank-like enemies that fire rockets, which will kill you with one or two hits until late in the game. These enemies will constantly exploit your weak weapons and fragile health by bum rushing your cover while they spam you with rockets. Suicidal enemies constantly swarm you and shoot you at point blank range, and you are pretty much helpless to stop this early in the game. It completely breaks the cover mechanics (your squad mates' stupidity doesn't help here). The game also loves to throw you into the middle of a big battle right out of a cut scene, catching you out in the open without any cover.
Thanks to all of these problems, the first third or half of Mass Effect is a supremely irritating experience. Mass Effect is not advertised as an action-RPG, and thus it is story-driven and very dialog-heavy. However, combat still comprises a third to a half of the game. Over and over, you will find yourself dying, because of dumb companions and/or the game Zerg-rushing you as you try to use cover. You do have a bunch of special powers that act as buffs or special attacks (biotics), but early in the game, they are too weak and they regenerate too slowly to have a major effect. As the game progresses and you gain levels, combat starts to get much easier, and more enjoyable. The core design problems never go away, but at least you can overcome them with brute force.
Combat is bad, and the game's dozens of side missions aren't much to write home about either. As I mentioned earlier, copy-and-paste design is one of Mass Effect's greatest flaws. The four or five major story areas are the only interesting areas in the game. The rest are short, repetitive, and shallow. The side missions often have interesting premises, but in completing them, you will see the same three or four building layouts numerous times. You can skip the side missions, but you will need to do at least some grinding so that you can become powerful enough to survive the game's horrendous combat. Otherwise, you can probably complete the short storyline in about 10 hours. It's easily the shortest main quest in any Bioware RPG to date. Even the story-related areas aren't that interesting. Most maps are small, dull and constricted – a problem with all Bioware RPG's since Neverwinter Nights (what ever happened to the days when Bioware could design a remotely interesting dungeon?).
Mass Effect also has all sorts of console legacy issues with its interface. It has supposedly been reworked for the PC, but it still has a few problems. The command system is very efficient and mouse-driven, but the inventory system is mind-bogglingly bad. Just like the lousy inventory system in most console ports, there is no paper doll, drag-and-drop inventory. Instead, the game uses a convoluted system of layered menus that makes simple inventory rearrangement a chore. It isn't a huge detriment to the game though, since it is not as loot-driven as a game like Diablo or Elder Scrolls.
Mass Effect has a unique universe and role-playing system, but it is riddled with some major design problems. When I read other reviews for this game, I'm puzzled by how few reviewers mention the inexcusable lack of polish and the poor design in the combat. Jade Empire also had a couple of significant gameplay problems, which makes me wonder about the direction in which Dragon Age is headed. I didn't feel compelled to finish Mass Effect, and I almost quit it a few times, but I did ultimately finish it, and that counts for something. It certainly has a lot of good qualities, and the problems are fixable if there is a sequel. The lack of single player RPGs on the PC makes the game at least worth playing if you are starved for a good one.