The Challenge Set, TimeSplitters Story Classic, can be found in TS2 and TS: FP. The Set is a homage to the original Story Levels of TS1, which consisted of starting at one point of a level, going throught it to collect an item and reaching a designated location, usually found at or near the start of the level.

Badass Buspass Impasse | But Where Do The Batteries Go? | Hit Me Baby One Morgue Time