These are split Unity files, as others have already said. To view the contents you simply need to join files of a similar name together with a hex editor (I used HxD in particular). After, the assets can be viewed in Unity Studio without a problem.
Here's everything graphic related: http://www.mediafire.com/download/ggm32f...Assets.zip
Here's everything graphic related: http://www.mediafire.com/download/ggm32f...Assets.zip