Force_of_Nature
[12] Conqueror
This. It also had one of the earliest create-your-own-map systems.
Indeed! Oh, I can not tell you how much of a blast it was creating levels in TimeSplitters 2 and TimeSplitters 3: FP! In TS3 you could create your own fully functional single player levels and share them online. I pretty much created my own story campaign online! TS2's editor was pretty solid too.