If you own a Xbox 360, you should own BioShock
When you begin the game, you'll soon find a wrench on the floor. But it won't be long before you start using a pistol, a machine gun and some other weapons, that certainly get very interesting (including a Napalm shooter and a Crossbow, which basically acts as a sniper). But beyond using weapons the combat the various types of Splicers (Splicers, which are basically some people turned into crazy, junkie freaks), you can use Adam (which is what the Splicers are after), which is a substance that rewrites your DNA, to attack enemies, using such abilities as an Electric wave, that stuns enemies, Incinerator, which lights your enemies on fire and attack them using bees that fly out of your hands and of coarse, there are a lot more abilities beyond these three that you can use against the Splicers.
There are also some RPG elements in Bioshock, most of which revolve around the way you can customise your character. You can use 'Tonics' to increase your ability to do certain things. For example, there will be Tonics that make you swing your wrench faster, make health packs increase your health more and ect. There are more than 50 Tonics in the game, so you do have a lot of choice as to what upgrades you want to give your character, but while this is a somewhat neat feature, you won't really need any upgrades for the first three quarters of the game, due to the combat being pretty easy, and even if you die, you'll just respawn in the nearest Life Restoration Chamber (which normally is less than 30 seconds worth of walking away), which about 70% of your health and all of your ammo.
Part of the games ease is due to the Splicers not putting up much of a fight. For the first three quarters of the game, its as simple as running up to them and shooting them with a shotgun, and occasionally you'll have to stun them with your electric shock ability to slow the faster ones down. But apart from the Splicers, there are Big Daddies for you to fight, and these are easily the most challenging fights in the game, more so than most of the boss fights in the game. These Big Daddies are large creatures (as the name would imply), in heavy armour that protect Little Sisters (who harvest Adam, and you need Adam, so to get the Adam, you need the Little Sisters, and to get to the Little Sisters, you need to get past the Big Daddy guarding her). These Big Daddies come in two variations, the Bouncer, that sports a massive drill for a weapon, and a Rosie, that use there Rivet Guns to attack you from a distance, both of which are very hard to deal with, without dying (although, if you die and come back from a Life Restoration Chamber, the Big Daddy you were attacking will not have healed, so you can quite easily kill them in that sense).
Apart from Big Daddies, you can fight, or hack the security devices, which also come in two variations. There is the security bot, which fires machine gun rounds at you, and a security camera, which, if it spots you, cause an alarm to go off, which will cause security bots to spawn and attack you.
If you hack a security camera, however, it will send security bots after any Splicer it spots, and if you can hack a security bot, it will follow you, attacking any Splicer that it spots. But these things aren't the only hack-able in the game. Throughout the game, you'll be hacking safes, vending machines (which is where you get your health, ammo and more from), gun turrets, ect.
But the thing I found most impressive about Bioshock, is its atmosphere. The game does an excellent job of making you feel like your really in an underwater city (and an extremely corrupt and unsafe one at that). The edgy, crazed Splicers, the destroyed environments and things of that nature help create an amazingly immersive atmosphere, an atmosphere that you really need to experience to truly appreciate.
But of course, the games presentation is a big part of the atmosphere, and the audiovisual presentation of the game is excellent. There are some excellent lighting effects used, and the enemy designs suit their purpose (which is Splicers essentially to be junkies for Adam and Big Daddies as protectors). The level designs are also excellent, both in quality and variation, as you'll be exploring a lot of different areas, including a vegetation theme park- like area, boiler rooms, areas filled with shops and stalls and libraries, offices and more.
The audio is also a big part of the games immersion, with Splicers talking, and even singing to themselves, an appropriate soundtrack that compliments the gameplay and the feel of the game and definitely the previously mentioned atmosphere. The game is set in 1959, and the music featured in small clips you'll occasionally be watching, and coming out of the jukeboxes you'll occasionally be passing, also help give context to the time in which the game is set. It’s also worth noting that there is a lot of voice work featured in Bioshock, and for the most part its done quite nicely.
Bioshock is an absolute must own for any 360 owner. The gameplay is excellent, the presentation is just as good and the atmosphere is remarkable. The game is a bit easy, but that would be my only problem with the game, and it’s not a big one, so if you own an Xbox 360, you should go out and buy Bioshock. The year isn't over yet, but its safe to say that Bioshock is Game of the Year candidate material.