VDrift is an openly developed, SDL-based car racing video game based on the popular Tokyo Drift; for Linux and Windows systems only, and with LAN capabilities.
Pong2 is a 2-player, ball game inspired by the legendary Pong game from Atari; with LAN capabilities, it is currently available for Linux systems only.
KBillar is the KDE-based billiard simulation; is highly customizable, LAN capable, and openly developed. It is also currently available for Linux systems only.