Roencia Game Creators is offering the "Indie Graphics Builder" for free, to those that back their zombie/alien survival game project. The IGB is essentially a collection from many of the build-your-own type graphic packs on their site. The package is usually available for $200 and contains around 9,000 files.
When backing "Stop the Planet: I want to get off" from the Kickstarter site at $75 or higher, you get:
1) The survival indie game
2) The rewards/prizes that come with it
3) A great package for building, prototyping, selling your games.
*Note, the attached video is old, and some files may or may not be in the IGB. Click the link to check the offer.