erm, I'm not quite sure what you mean with "game modules", cause I only know one "game" module.

LS will download every module the choosen Theme needs (if you let ls access to the internet of course ;) )
so non-theme-includet-but-want-to modules have to loaded manulay:
open the \themes\"themename"\theme.rc (mostly, or the file with the *NetLoadModule lines will be in the config folder, search for that).
copy a *NetLoadModule line and paste in below the other *NetLoadModule lines. now write behind that your choosen module name (example: zip file is called: modul1-2.4_beta.zip your line has to be: *NetLoadModule modul1-2.4_beta )
now, place the module zip file in your:
litestep\modules\archive\
folder. Opne the zip and read the txt which settings this module has and set them in the theme.rc (or whatever.rc you're now from the theme)

last one is to recycle and pray that your settings are well (ok, I do that)