This is coming from a person who does not like first person shooters: Timesplitters: Future Perfect is an excellent game with tight control, fun gameplay, funny dialogue, and enjoyable characters. The time-travelling storyline allows settings and weaponry ranging from revolvers in the '20s (1920's) to laser rifles in the '20s (2420's), which makes for great variety.
I haven't played it online (I have a GameCube, and "gamers do not want online gaming" -Satoru Iwata), but I've played other games on the 'net with my girlfriend's PS2. I don't understand how anyone could have a problem with children doing this; the only damage other players can do to you while playing is to your character or to your pride as a gamer, and both heal fast enough. Also, though I agree StarFox Assault is an excellent game, it's not a FPS in any way; please stop calling it one.