The source available via Subversion has basic sound support (using SDL_mixer). Also, it appears that frame buffers were broken in G3D version 6.10. It was released in July, and the G3D forums mention several bug fixed made to it in October. Since v7.0 is supposed to be quite different, and just had its first beta release, I'm not sure if I want to try it yet. We'll have to see how it goes.