On Saturday I went down to the local Big W and picked up BioShock for the Xbox 360. Needless to say the bulk of my weekend was taken up immersed in the world of Rapture, under the sea.

BioShock is one creepy game. It's dark, atmospheric and claustrophobic. As you wander the halls of Rapture, you'll hear creaks from the walls around you from the pressure of the sea outside. You'll hear the mindless ravings of splicers (citizens of Rapture driven mad by genetic upgrades gone wrong) in nearby rooms, waiting to assault you as you enter. You'll feel cold, wet and genuinely freaked out most of the time.

Because the city of Rapture is at the bottom of the ocean, BioShock makes full use of cutting-edge water effects. The pools of water on the ground ripples as you cross. Waterfalls formed by cracks in the ceiling blur your vision as you walk through them, and the water "sheets" off the "camera" as you emerge. Large icy stalagmites melt into puddles of water when you hit them with fire. It all looks amazing.

Speaking of fire: The amount of weapons and weapon customization is just ridiculous! There are seven or eight 'traditional' weapons (pistol, machine gun, shotgun etc), each with up to three kinds of ammunition. But on top of that, there is a whole system of genetic upgrades known as 'plasmids', which give you superhuman powers. For example, you can use the Electro Bolt plasmid to shock an opponent, stunning him long enough to shoot him down or bludgeon him to death with your wrench. Or use the Incinerate! plasmid to light an enemy on fire, causing him to run around in confused pain while you pick him off (or simply wait for him to burn to death).

The cool part is the innovative ways you can combine plasmids. For example, you can light an enemy on fire, and wait for him to dive into the nearest pool of water. Once he's there, hit him with an electric shock to kill him outright.

As well as weapons and plasmids, there is another category of upgrades known as 'gene tonics'. These give you special physical abilities such as reduced damage in combat, faster movement or better hacking skills.

Hacking! That's a whole new facet to the game. Throughout rapture there are numerous mechanical devices, some helpful, some dangerous. For example, security cameras will send autonomous flying bots to kill you if they see you. Vending machines allow you to purchase first aid kits or ammunition. You can hack any of these machines in a number of ways (the default being a great little mini-game reminiscent of Pipe-Mania). Once hacked, the machines work for you. Security cameras will scan for enemies. Gun turrets will ignore you but shoot bad guys. Vending machines have more stuff available at cheaper prices. You get the idea.

Adding to the overall creepiness of the game are the 'Little Sisters' and their protectors, the 'Big Daddies'. Little Sisters are young girls who have been corrupted somehow, and stalk the halls looking for corpses from which to harvest genetic material. The Big Daddies are ... well, at this point I don't know what they are. All I know is that they're big, and incredibly difficult to kill. The way they shake the environment as they walk is enough to make you want to turn off the Xbox and curl up in a foetal position behind the couch.

As you explore Rapture, you find small audio clips which help unravel the underlying story. It's a great way to get to know the history of the place without resorting to cut-scenes etc. I'm only a few hours into the game so I don't know much yet, but I'm listening to every audio clip I find, slowly getting to know the characters (some long dead, others still alive somewhere in the city).

So far this has been one awesome game, and I expect it to only get better the deeper I get. I can definitely see myself playing through it again so that I get a chance to explore all the nooks and crannies that I've missed so far. Highly recommended!