I'm a hobbyist developer working on an FPS called "Forever War".
Special about the game is that the world is 100% destructible (like in Worms), so there are entirely new combat tactics possible - for example, you can dig tunnels and attack your enemies from behind, or bury them in the ground.
The technology behind the destructible world is the PolyVox technology, which is used in a slightly modified form to support smooth geometry and paging.
Bullet is used for all objects in the world, like barrels, the player, weapons, enemies, and ... bullets.
A tech demo is available in which you can shape the world in "god mode" or interact with the world as player and fight against the first enemy type.
Homepage (with further information and downloads):
http://foreverwar.sourceforge.net/
Screenshots:
World editor:
Fighting:
