Unvanquished is a fast-paced, futuristic FPS with RTS elements, pitting technologically advanced humans against hordes of highly adaptable aliens. The player can choose from either team, providing a fresh gameplay experience on both sides of the conflict. The game is under highly active development, with a new alpha release being made at the beginning of each month.
Good fun, nicely balanced, very original. Development is fast and updates are released frequently.
The graphics are nice (some great lighting!) but some areas need some big improvements (some of the weapons are pretty fugly, for example).
Another point is that there aren't that many people online, but I'm sure this will change soon!