Program: Wormux (Worms clone)
License: Open Source/GPL
Description: A Worms clone.
Have the mascots of your favorite free softwares battle in the Wormux arena. Using dynamite, grenades, baseball bat and others bazookas,... exterminate your opponent in a 2D toon style scenery and a funny environment.
Each player controls the team of his choice (penguin, gnu, firefox, wilber,...) and must destroy his adversary using more or less casual weapons.
Although a minimum of strategy is required to vanquish, Wormux is pre-eminently a "convivial mass murder" game where, turn by turn, each member of each team attempts to produce a maximum of damage to his opponents.
I think this game would be great to have portable (if possible). I haven't downloaded and installed it yet to see the space taken up.