is a humans-versus-aliens first-person shooter game, derived from Tremulous
It's currently in alpha, has seen a few releases, and is undergoing some rapid development. Things may sometimes be broken, inconsistent or imbalanced; but that's work-in-progress for you.
We have weekly dev games on our Development and Testing Server. These are on Sundays at 20:00 GMT.
(Yes, we know that our logo's missing its corners. That's Google's fault.)