BZFlag is a 3D, multiplayer, tank battle zone, capture the flag game that pits players against each other in a networked environment. It runs on Windows 95/98/NT/2000, Linux, MacOS 10.x, Irix, Solaris, and others. An OpenGL accelerator is highly recommended, but it is playable with 3D in software.
papercut is command line based rock, paper, scissors game for Unix based operating systems like GNU/Linux, BSD, etc. A user can play the game by entering their choice of rock (R or r), paper (P or p), or scissors (S or s). papercut also stores user statistics, i.e. number of wins, losses, and draws.
Bastet ("bastard tetris") is an ncurses Tetris clone which is harder than every other tetris released. It is based on a heuristics engine which tries to detect which block you need or don't need, and then gives you the blocks that you don't need. For instance, if you usually play by leaving long "canyons" one square wide and then waiting for the long "I" block, you'll have to wait till eternity before you see it. The heuristics have been worked on for some time and are quite nasty.
KBall is a game of skill and reflexes suitable for all ages. The idea is to move a ball around the map without falling or running out of time, and getting the prizes, in order to reach the exit. The map has different traps, such as slides, pushers, jumps, falls, and walls, etc. Maps are viewed from top view, and the walls and player's ball are real-time rendered in beautiful 3D. There is a map editor available inside of the game, to make custom maps.