The fact that all the games are priced the same should be your first hint
be it for x360 or pc (number of discs determines price)
Second big hint should be: you have to copy a crack off the disc

//edit: i believe that at some point they started modifying the installer of the game itself so that the crack automatically replaces the original exe without the user having to copy it over manually
(as is the case with the downloaded warez versions of the same games)
and thirdly: you cant play their games online
As for xbox games...
heres an example of the requirements "Requirements : Fantasy Shooter
Release: Jul 12, 2011 »
ESRB: Teen
You MUST HAVE (11th wave)
iXtreme Firmware v1.51 [Hitachi Drive Only]
iXtreme v1.6 [Using Activation Disk] or
iXtreme v1.61 [or later] to play.
((((( iXtreme LT Recommended )))))"
"You MUST HAVE (13th wave)
iXtreme LT 2.0 Recommended"
or a more recent game: