Note to the three tsc's above:
Those tsc's work together in a very particular way and they offer a lot of functionality, I yet have not written paragaphs to them;
Their actions are responsible for loading levels in total, and proofed useful for some playchangeing options.
This file adds the artifacts to game; A line looks like this:
Function NOM_LOD FLAG TT AddArtefact IT_ARTIFACT1 FLAG_LEVEL1 32
As you can see it first takes in an artifact name, then the Level name it need to be placed in and then the "TT" variable. Which is probably TT-id / text. More information
This file is actually quite interesting.
Rtc.tsc is responsible for all the the in game cutscenes.
From line 27 to line 38 are definitions for the death scenes. If you remove them, you effectivly remove them from the game.
I haven't played around much with this file, so further research is definitly needed.
Extra adds all bonus content in, so unlockable images, cheats, videos, minigames; Tho the minigames are only visually added from what I know;
The menu.tsc.
.. I don't really know what it does, to be completely honest with you.