Microsoft has confirmed that the addictive first-person puzzle game, Portal, which first appeared as part of the superb The Orange Box package , will be released on the Xbox live arcade on Wednesday October 22nd.

Portal Still Alive will feature the original game, plus 14 new challenge maps exclusive to the Xbox 360 and 6 advanced maps!

Weighing in at approximately, 700MB and costing 1200 Microsoft Points, Portal Still Alive will be available from 9am GMT on the 22nd.

They'll also be 12 achievements on offer including the imaginatively title Vanilla Crazy Cake, where we'll have to beat all advanced chambers and Is Anyone There? which will require us to complete the game without ever taking a bullet

More cake anyone?