Bioshock's only a week away from launching in Australia, but for those who simply can't wait, a 1.3GB large demo version is now downloadable from Xbox Live. The only question left to answer is: is it worth your precious bandwidth?

　　Here are a few reasons why you should download it: firstly, it's a great teaser for the full game. The demo takes place right at the beginning of Bioshock, so you'll be introduced to the underwater world of Rapture in an appropriately creepy and enthralling way. Most of the game's major game mechanics and big name characters are also on show. You'll get to see a few of the weird and downright eerie Little Sisters, as well as see their destructive Big Daddy guardians in all their giant drilling glory. While you won't actually get to take on any of the Big Daddy's, you will get your fair share of action facing off against Splicers, the strangely mutated and not-at-all sane denizens of Rapture. These enemies are just as unsettling as the Little Sisters--we came across a female Splicer early in the game wearing a bunny mask and whispering soothing words into a pram. When we disposed of her and looked into the pram, all that was in there was a large pistol. Weird. These Splicers also sport what seems to be pretty smart AI. Lone Splicers will often run for support before taking on your character, and exhibit smart behaviour such as running straight for water if you set them on fire. You'll also come across plenty of mechanical opposition--floating machine-gun sentry pods patrol some hallways, and can be extremely tough to take down with normal weapons. Of course, bullets aren't the only way to deal with these sentries--Bioshock also allows you to "hack" into these turrets, which will result in them attacking any Splicers you may come across. Hacking takes the form of a mini-game, which sees players having to create a power path by arranging and swapping a series of pipes.

　　As well as conventional weapons such as a pistol and sub-machine gun, this early level of Bioshock also introduces players to the concept of plasmids. Plasmids essentially are enhanced superpowers your character can use, and you'll get access to them right from the start. You'll get to play around with two in this short demo--one which allows you to shoot lightning bolts from your fingertips Emperor Palpatine-style, and another which sets your enemies on fire. Plasmid powers are not inexhaustible--you'll need to find plasmid injection packs to continue to use them. Plasmid powers also introduce you to the open-ended gameplay concept Bioshock's developers have long spoken about, with these new powers giving you more options in which to dispose of your enemies. Using the electricity power on enemies standing in a pool of water, for example, will result in a nasty life-ending shock for them (pun intended).

　　The game simply looks great as well--Bioshock's water effects are quite realistic, especially at the start of the level where your character has to swim away from the wreckage of a crashed plane. The same goes for textures and lighting effects throughout the whole demo level.

　　And here are some reasons why it's not worth the bandwidth. First of all, at 1.3GB, it's a pretty hefty file. Secondly, the game is due out in Australia on August 24, so the wait won't be too long before you can get your hands on a full copy of the game. Finally, the entire demo--if you decide to rush straight through it and not bother to take in your surroundings--takes about 20-30 minutes maximum to finish.

　　But then again, that's what teasers like this are for: to give you the briefest of tastes and leave you wanting more. Check out GameSpot's full coverage of Bioshock by clicking here .