The newest weekly sale on the Humble Bundle website brings shoppers the Humble Puppy Bundle, in partnership with Puppy Games.

A percentage of proceeds from the Humble Puppy Bundle will go to support GamesAid.

The Humble Puppy Bundle includes Ultratron, Droid Assault, Revenge of the Titans, and Titan Attacks. Buyers who play more than the average price (currently $3.47) will receive Steam keys for all four games. The soundtracks of Ultratron and Revenge of the Titans are also included. DRM-free versions of the games are also available.

If the bundle raises over $150,000, Puppy Games will release the source code for all four games. So far, over $72,500 has been generated. The bundle will run through December 26th.

Puppy Games was founded in 2002 by friends Caspian Prince and Chaz Willets. With the release of Revenge of the Titans in 2010, the two developers were able to focus on developing games full-time. Follow Puppy Games on Twitter to keep up with their latest developments.