Mass Effect is a flawed but amazing experience, which most fans of shooters and/or RPG's can enjoy.
The game has you starting out as Commander Shepard, whose appearance, gender, and past life you decide. You're able to customize almost everything about the character, though it's probably easier to just go with the default design the game gives you. You're able to choose from 6 character classes for your character; 3 normal classes, and 3 combination classes. The 3 normal classes are "Soldier", "Engineer, and "Adept". Soldiers are, as their name suggests, weapon experts. They are able to fight skillfully with any weapon, and can be a valuable asset in battle. Engineers are Tech Specialists. Using an item called the Omni Tool, the can decrypt security systems, repair or modify equipment, disrupt enemy weapons and shields, and heal their allies. And lastly, Adepts are biotic powerhouses. Biotic power is the ability to affect the outer world with the power of the mind. Adepts are used to manipulate objects in the environment, including nearby enemies, and can also use their powers to strengthen their party and weaken enemies. The 3 combination classes are the Infiltrator, which is a combination of the Soldier and Engineer, the Vangaurd, which is a combination of the Soldier and the Adept, and the Sentinel, which is a combination of the Engineer and the Adept. These 3 classes are most useful, allowing the ability to use the abilities of two classes simultaneously, instead of being stuck with one single skill, and having to depend on your AI squad members to cover your weaknesses.
Once you have your character tweaked and developed the way you want, you start the story. As said above, you start out as Commander Shepard, who's past you decided. You are a Commander of the Systems Alliance Military, and aboard the Normandy, a highly developed spacecraft, you represent Humanity's first and last line of defense against a large and dangerous galaxy. After a short introduction, you start your story by fighting an attack by the Geth, an Intelligent AI race of machines, on the world of Eden Prime, where a very important device called a beacon has been unearthed. After the mission, Commander Shepard uses the beacon accidentally, and has an unexplainable vision of war and destruction. Along with this strange vision, Shepard also finds out about Saren, a traitorous Turian Spectre, who is in control of the dangerous and giant race of Geth that attacked Eden Prime. These are the two aspects of the story that leads Shepard on a long and dangerous quest to save the galaxy from an ancient threat, and it can be insured that the story has enough twists and turns to keep you interested till the very end.
One of the first things you notice in Mass Effect is the unique conversation system of the game. When interacting with another character, you will have a "wheel" appear at the bottom of the screen, which will show a number of things you can say in response to the other character(s). Instead of saying the exact thing you want, you choose what question or statement you would like to get across, and Shepard says in his own words what meaning you wanted to get across. This helps make conversation much more fluid and natural, and as a result: More fun to do. Conversation is a big part of the game, and can determine how characters interpret you, what they do, and how much help you can get through the game.
Conversation is also the main way of gaining Paragon or Renegade points, which is the morality feature of the game. Paragon is associated with good, while Renegade is associated with bad or evil. Being associated with Paragon and Renegade can each give you great assets, the most distinguishable of which would be the ability to bring up your Charm or Intimidate skills. Charm is associated with Paragon, while Intimidate is associated with Renegade, and each skill unlocks special dialogue options in conversation, which can be great assets, due to you having the ability to talk yourself out of a hard fight or get a special item from someone. Each morality can also effect how people see you, and whether they like you or not can be very important in the middle of an important mission or etc..
When not conversing with NPC's, you'll mostly be in combat. Combat in Mass Effect is very solid and works well, using a 3rd Person shooter approach and a developed cover system to help you stay alive while defeating your adversaries. The gameplay of combat doesn't get old, and is just pure satisfactory when you get past a hard battle, or defeat a difficult boss. Your able to choose from 4 different types of weapons when in combat: Pistols, Shotguns, Machine guns, and Sniper Rifles. Each weapon has it's own strengths and weaknesses, and can be the best choice for any given situation. Thanks to a newer technology developed in the future, the amount of ammunition you have is of no concern, since each gun can shoot thousands of shots without reloading. However, you will have to be concerned with your gun overheating, which will be a result of shooting your gun too many times in succession. If your gun overheats, it become useless until it cools down, leaving you defenseless until that happens. Another way of fighting is to use Biotic Power, which can be chosen very quickly and easily through a menu accessed by holding R1 in battle. You can gain more biotic powers through upgrading your skills, and can be used in a variety of ways, such as developing a protective field around your character to prevent damage, bringing back to consciousness party members who have been defeated in battle, and allowing you to unleash a devastating powerstrike from a shotgun. These skills, however, must be given a chance to recharge, which can take some time. While it may be tricky at first, you can eventually learn to switch between using guns and powers in battle, executing flawless attacks and defenses, and making yourself feel like a god.
Not everything about the gameplay is good though. When exploring most planets, due to the large scale of the environment, you will have to use an all-terrain vehicle called a MAKO to get around. While this may not sound bad at first, the MAKO has terrible handling and is hard to keep control of. You will constantly somehow manage to miss enemies with the MAKO's weapons (a machine gun and an explosive turret), even though they are right in front of you, and when you need to make repairs to the vehicle, it will sit there and not be able to move or use it's weapons, which will essentially screw you into a "Critical Mission Failure" screen if a powerful enemy happens to go around the cover you are behind. However, you are usually able to get in and out of the MAKO as you please, which will allow you to fight without worrying about the status of your vehicle.
You get 6 squad members early in the game to fight with you: Kaiden, an Adept Alliance soldier on the same ship as Shepard, Ashley, one of the few soldiers on Eden Prime that are still alive when Shepard reaches it, Garrus, a turrian C-Sec officer who greatly desires to bring Saren down, Wrex, a Krogan Bounty Hunter who is hired by the shadow broker, Tali, a quarian machinist who is on a pilgrimage to bring back something great to her people, and Liara, an Asari researcher who knows more than anyone else in the galaxy about the ancient race of Protheans. Each person has strengths and weaknesses in battle, and depending on the situation, they can either be an asset or a hindrance. You can bring any two members into battle at a time, and choosing members to cover your and each other's weaknesses can be greatly effective in getting past a tough battle.
Upgrading your skills in Mass Effect is another great need to get past tougher battles later in the game. When you level up, both you and your squad members gain experience points, which you can use to increase many of your different skills. You can upgrade skills such as Shotgun or armor, which will grant you the ability to use new skills and items, and your can also upgrade biotic skills such as warp and throw, or tech abilities such as Decryption and Hacking. Each skill serves an important purpose, and will allow you to either do things with more power or accuracy than you could before, or do things you couldn't do before (hacking or decrypting) because your skill was too low.
The graphics in Mass Effect are amazing. Characters in the game are deeply detailed and rendered, with wrinkles, eye depth, and other small, misc. features being as apparent and important as the general well-done structure and clothes of each character. Environments are either bright and spacey, ruined and aged, or lush and beautiful, all 3 of which are spectacular to see and fun to explore. The music is also great, with gentle tunes that play when the character is exploring a building or planet, to fast, epic music that plays when in the middle of a battle, large or small. Each tune fits the mood perfectly.
The storyline in Mass Effect can be beat in under 15 hours. However, there are tons of compelling and fun side quests to do in Mass Effect. From collecting items to search and rescue, missions in Mass Effect are greatly varied and will usually have great rewards for you to make it worth you while. Hours can be spent just exploring planets and reading up on information about the galaxy. Doing things besides the main story can greatly increase the amount of time you put into it, and can also give major replayability due to the amount of things you may have missed.
Mass Effect is a flawed but amazing experience, which most fans of shooters and/or RPG's can enjoy. Whether it's for the exciting gameplay, the great cast, or the fun explorable environments, there's most likely a good reason to enjoy this game.