Natural Selection 1 did this in 2001 and is 1000 times better. Game is amazing play it folks, oh wait it's dead nvm.. Rip..
Objective based fps games are an extreme niche (actual objectives with multiple phases), but damn they are really good when it works. Games like rtcw/ET, dystopia, and NS are some of my favorites, but the player base was never there or died off fast. NS2 was really fun, but it just didn't keep people playing.