Hey,
My kids, boys 4&7, find working in KDE is fine.
Once they work out where the Debian/Games menu is.
Sometimes if I want to help out I will put Debian/Games/Arcade on the KDE
Panel.
The other thing which confuses them is the location of TuxPaint, under
Graphics, as everything else they want to use is located under the Games
menu. So sometimes I place a link to TuxPaint next to the Arcade button on
the panel, I also change the default for TuxPaint to 800x600, to give a bit
more screen realestate to draw on.
The biggest technical issue isn't trying to lock down the environment as they
enjoy playing around and there is only so much they can do anyway. The
biggest issue is ensuring consistency with Direct Rendering as a lot of the
games which interest them the most need it for reasonable performance,
SuperTux, TuxRace, PlanetPenguin Racer, TuxPaint, Atomic Tanks, Egoboo.
That said knoppix generally does a pretty good job of setting up direct
rending.
If there was a d-jr, t4k CD, I could give them copies and they could pass onto
their friends, grandparents, ... for a bit of viral marketing!!
Mark