Developer Valve has teased fans with the prospect of an early release for the PC and Mac versions of Portal 2.
This will occur if enough fans put enough hours into a collection of indie games available through Steam. The 13 games, brought together in what is being called the 'Potato Sack' collection, can be purchased for £27.22.
Any gamers who already own some of titles, which includes the likes of Super Meat Boy, Toki Tori, AAAAAA!!!, can also access their existing copies to contribute towards the goal.
At the time of writing seven games have been played to the extent required by Valve, with a further six still available for play. Currently the game is on target to launch around ten hours early, which will be around 9:00am tomorrow morning though there's still hope to bring this further forward.
Note, too, that this release time only applies to the digital Steam version of the game. The Xbox 360 and PS3 SKUs will still release in the UK as planned this Thursday.