The Command & Conquer brand may be synomonous with real time strategy, but back in 2002 Westwood created Command & Conquer: Renegade - a first person shooter set in the C&C universe. While the game itself never really took off the multiplayer that featured many elements lifted from the RTS genre as two teams battled for resources with the objective of destroying the other team's base.
It's been more than a decade and a group of fans - Totem Arts - have now developed an unlicensed tribute of sorts - Renegade X - using Unreal Engine 3. The game is available for download on the official website.