Heroes is a funny game similar to "Tron" or "Snake" it are compiled for linux but the source is open and free. The screen (when you're playing it on a 1920x1200 screen) is similar to the ds screen (both graphically and size) source
is attached (diff file, original and compiled for linux)
Site:
http://packages.qa.debian.org/h/heroes.html
http://heroes.sourceforge.net/