Pipepanic is a great game and it's also available for the Sharp Zaurus, Opera Widgets and the Nokia 770 -> http://www.thunor.org.uk/pipepanic/index.html
GNU Robbo I have enjoyed for Linux ( http://gnurobbo.sourceforge.net/ ) and the Sharp Zaurus version is here -> http://www.thunor.org.uk
If you play Gameboy games (GB|GBC|GBA) on Linux and require a front-end then I can recommend RbVBA -> http://www.thunor.org.uk/rbvba/index.html
Great GPL stuff.
Regards,
Jane