The developers and studios behind hits such as Braid and Machinarium have created a five-game charity pack for Mac, Linux and Windows PCs, costing as little as $1 or as much as its purchasers care to spend.

Braid's time-twisting platforms and Machinarium's stylish point & click adventuring are joined by Osmos's chilled-out action and robot battlers Cortex Command and Revenge of the Titans in the "Humble Indie Bundle #2".

Revenge of the Titans is the newest kid on the block, the Bundle marking its launch, and along with Cortex Command promises free updates as more features are added. All but Revenge have already picked up awards at the prestigious Independent Games Festival.

By default, proceeds are split equally between each of the five development companies and the charities - Child's Play children's charity and the Electronic Frontier Foundation - with a small tip going towards future Bundles.

However, even the minimum transaction of $1 (€0.75 / £0.64) can be divided up into specific amounts destined for the developers, the two charities, and the Humble tip jar.

Child's Play was set up by the creators of the Penny Arcade webcomic and has since become a popular charity cause, this year raising over $1 million to provide children's hospital wards with toys and games, while the Electronic Frontier Foundation is a digital rights non-profit.

After the first day of Humble Bundling, nearly $450,000 had been raised, with an average purchase price just north of $7, and some notable games industry personalities dropping up to $2,000 each.

The previous Humble Indie Bundle ran for a seven day stretch, pulling in just shy of $1.3m. If this second promo follows suit, there's until December 21 to make the most of it.