These ebuilds come from http://games.gentoo.org/.
If you have some problems, go to the official site first.
marbleblast-demo : race marbles through crazy stages ( http://www.garagegames.com/pg/product/view.php?id=3 )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a zugaina
For Paludis use this rsync : rsync://gentoo.zugaina.org/zugaina-portage
If you have a problem : ycarus(-at-)zugaina.org