Crystal Core is a FPS quest-based game written with Crystal Space and Crystal Entity Layer. The game is based on a science fiction story. The player and his or her companions crash on an alien planet where they discover that the original intelligent inhabitants are now extinct due to an invasion of semi- primitive aliens from a distant planet. Your goal is either to destroy all aliens or escape the planet alive. To accomplish these goals you have to use alien technology and try to interface it with the broken ship that you arrived with.
EDM is a fork of Sauerbraten (http://www.sauerbraten.org/) which is in development but playable. It features several multiplayer game modes like Deathmatch and Instagib, dynamic map model physics, enhanced particle effects, unique weapons and powerups, and more. Maps can be edited with other players online.
Adanaxis is an action game where the fundamentals of space itself are changed by adding a fourth dimension to space. Initially, it's like learning to play a 3D FPS for the first time, as the hand and eye have to learn a whole new type of coordination. The gameplay involves rapidly blowing things out of the sky, with the usual assortment of enemies, allies, weapons, and power-ups, together with commercially sourced graphics, audio, and voice acting.
Alpha Shooter is a 3D first-person shooter game with a sci-fi setting. It features multi-platform support (Linux, Mac OS X, CygWin, and Windows) and, since version 0.1.0, its own reusable game engine (Neutron). The game and its engine will evolve over time to incorporate simulated physics and AI, networking, audio, scripting, and more.