The code should work, but even without it I was able to get it at the price of £5.99, which works out to be $8.37
A good time to snag this game while it’s cheap.
If you do consider purchasing this game, be sure to grab DSfix and edit the .INI files for a better game experience, which you can find over here: http://darksouls.nexusmods.com/mods/19/?
Good deal. £5.69 (coupon price) works out to 9.36 AUD according to Google. Under ten bucks is a bargain indeed for this highly rated game.
Or pay $70 USD versus $30 through Steam thanks to regional markup:
http://www.steamprices.com/au/search?dark+souls