Enter Cyrodiil... after setting aside 200 hours of your time
Oblivion is the fourth edition to the Elder Scrolls series, a franchise of role playing games developed by Bethesda that have risen to fame for allowing players to embark on an epic journey and become the character they want to become. Even years after its release, Oblivion is an amazing adventure full of surprises, mysteries, and interesting locations that one could easily spend up to 200 hours playing it .
The main quest line in Oblivion follows your character as he or she goes on an adventure to try and stop the evil Daedric forces from overrunning Cyrodiil. The Daedra themselves are pouring out of Oblivion gates, which begin dotting the land after the Emperor and all of his known sons are murdered. Because of the Emperor's death, there is no one available to relight the Dragonfires, which prevent the Daedra from coming over. The main quest itself is pretty lengthy and will take you all over Cyrodiil. Of course there are always side quests that you can embark on, and there sure are a lot of them. My current character has completed over 130 quests, and I haven't even finished the main quest line yet. That should give you an idea of how huge the game world is.
Right from the get go you are free to go wherever you please. After the lengthy tutorial mission, you are thrust into the world of Cyrodiil and the game literally tells you to just go out and see what you can find. The game world is absolutely huge. A lot of people will probably feel overwhelmed at this point, because the possibilities are endless. Will you head into the woods and explore some caves, or visit a nearby town to meet some people? Will you continue following the main quest, or will you try to join a faction? The amount of things to do in the game is staggering. Thankfully, all of the major cities in the game can be fast-traveled to as soon as you leave the prison, so it's easy to move around, find quests, and sell/purchase gear. I should also mention that there are hundreds of caves, dungeons, mines, villages, and other locations to discover and search for loot.
Speaking of quests, it's very important for a game like this to include a healthy variety of tasks for the player to take on. Despite the fact that a lot of them are fetch quests and require you to head into a dungeon and retrieve something, almost all of them are entertaining to do and satisfying to complete. When I was first starting to play, I walked into a nearby town and within 30 minutes had more than 10 active quests. You can pick up side quests by speaking to people or even listening in on conversations. Interacting with people can be interesting once in a while, but most of the time you'll be selecting a topic and listening to them throw large amounts of knowledge at you.
You can also join one of the various factions in a game, which is highly recommended because they are a lot of fun and can provide you with some interesting gear. There is the Fighters Guild and Mage's Guild, both of which are pretty straightfoward. There is also a Thieves Guild where you'll be tasked with stealing things, and an assassin's guild where you (surprisingly) murder people. Each guild has it's own storyline instead of a random string of missions thrown together without any continuity. I should also mention that the quest log in your journal is extremely easy to read, as each quest is divided in step-like form and written from the first person point of view.
You'll likely spend a lot of your time with the game just exploring Cyrodiil. It's surprising how much fun you can have by just taking a stroll through the woods, discovering caves and mines, going for a swim in a river, and climbing mountains. And all of it is beautiful. Oblivion is nearly 4 years old, but it the game looks fantastic. Running through the fields on a sunny day, you'll notice the vibrant green of the vegetation, the bright blue sky, and the yellow and red flowers as you pass by. The only gripes I have with the visuals is the large amount of pop-in. Grass will literally materialize in front of you as you move forward, and far off hills and mountains are blanketed in low resolutions textures that will fade into detail as you get closer. Most of the characters in the game are also ugly looking. Out of the huge amount of NPCs in the game, I saw but one female that I thought was even remotely attractive. But if you're willing to look past these flaws, you'll find that the game is most definitely pleasing to look at.
The sounds and music of Oblivion are also pretty well done. There are only a handful of songs in the game, but surprisingly I wasn't annoyed in the slightest at the repetition. The music is majestic when you are wondering the countryside, calming when you are shopping in a store, and eerie when exploring a dark cave. It all just fits right into place in the world of Oblivion, and helps make the experience more enjoyable. The voice acting, on the other hand, is different in quality. There are two big name actors--Patrick Stewart and Sean Bean--and they deliver their lines very well. Unfortunately, there are only about 10 other voice actors. Every Argonian female sounds the same; every male Orc sounds the same; every female Khajiiti sounds the same. You get the point. It can be a bit tiring hearing the same people over and over again, and there are some that will make you wish you could just mute them (the female Orc is so annoying).
Cyrodiil is definitely not without its villians, so you'll spend a lot of time battling foes to the death. The combat is..... okay. Rather than relying on stats like previous games, it's solely based on the condition of your weapon, your combatant's armor, and whether or not you are physically hitting them. Most of the encounters looks a bit awkward - it's not uncommon for you and your opponent to stand still staring at each other with shields raised. There is a bit of button mashing involved, but you can't just charge full on and expect to destroy everyone. Hitting their shield, for example, can cause you to stumble, opening you up for hits. The same can happen to the enemy as well. Because of this, you'll actually need to plan out when you are going to strike. You can also cast magic with the press of a button, but playing as a warrior-type character is frankly much easier than playing as a mage as you don't need pinpoint accuracy and you don't have to worry about magicka management.
I suppose I should talk about the leveling system in the game, because most people will find it to be a hit or miss. Basically, the game does rid of experience points and instead has you choose 9 major skills that you want to focus on throughout the game. These will define what character you will become. So, if you want to be a Dark Elf that sneaks around and casts fireballs, you'll want to choose Sneak and Destructive magic as major skills. In order to level up, you'll need to practice these skills to raise them, which will advance you in level. A lot of people don't like this system, especially since enemies scale to your level and one can easily advance by swimming into a corner.
If you're looking for an extremely long-lasting role playing game that lets you be the character that you want to be, Oblivion is a great choice. It combines a enormous amount of quests to take on, a large world to explore, an interesting plotline, and impressive visuals that will likely keep you going for months. Just make sure you don't pick Speechraft as a major skill. Seriously.