Well as far as the toys go, open up yast and go to install software, and change the filter to package selection I do believe. It should show a directory on the right titled Amuzement and should have toys and games and subdirectories. Just cycle through there and install what looks fun. As for as the backgrounds and what not go, I don't have much for you in Gnome, but if you are a KDE user like myself, then check out www.kdelook.org.
I think that you will enjoy what you find there. Good Luck!