Card Monsters lets you play a creatures, instants, and sorceries. You to play the game against a computer-controlled opponent. Currently there are over 300 cards, and you can play in constructed, sealed, and draft mode. The program can automatically download all of the card pictures. The GUI is basic but very usable.
GNUSTEP Live CD contains a lot of software for GNUstep, a free implementation of the OPENSTEP framework (which is also directly used in Mac OS X as Cocoa). It includes excellent applications for RAD (GORM and ProjectCenter). The CD is available for i486, AMD64, Apple Mac PowerPC, and Sun UltraSPARC computers.
Gweled is a GNOME version of a popular game (for PalmOS, Windows, and Java) called "Bejeweled" or "Diamond Mine". The aim of the game is to make an alignment of 3 or more gems, either vertically or horizontally, by swapping adjacent gems. The game ends when there are no possible moves left.