How can you revive something that's not dead?

Yeah, but it's not as popular as it used to be...

Actually, I've played UT2004 more as a single player game than i ever have as a multiplayer one. There are several difficulty bots and you can combine them any which way you please. The campaign is pretty much a tournament style sort, where you play each map and the bot difficulty starts ramping up as you go higher, but there is no story whatsoever in it. It's not a thinking game at all, you just run and gun until you win or lose (it does require skill though).

Playing quick matches can be fun too if you tweak the bots to play at your level. The only thing you're really missing are bragging rights, fun things and crazy stunts human players can do or say, but other than that, it can be entertaining. Playing with a human friend who's somewhere near your skill, though... that is pure bliss.