Nazghul and Haxima
Nazghul is an old-school role playing game engine modeled after Ultima V.
Haxima (contained in the nazghul-haxima package) is a game written using the Nazghul engine.
Simply either run "haxima" or select Haxima from the "Games" menu. A tutorial is included for those who are unfamiliar with this style of game, and some documentation for players is in /usr/share/doc/nazghul-haxima-version/USERS_GUIDE. Saved games are stored in a .haxima directory in your home directory.
Nazghul is a role playing game engine; the games themselves are actually written in the Lisp dialect Scheme plus some specialized . You can look at the plain text source for Haxima and find hints or even modify the game. If you're ambitious, you could even write your own game. Complete documentation lies under /usr/share/doc/nazghul-version/.
(these need to be shrunk or thumbnailed)