Then how do you even know about it's gameplay?
Ever heard of Youtube?
and kid, Gmod can run on an XP OS, the only thing you have to watch yourself on is the amount of addons you have in your folder.
I have actually been thinking about telling Garry Newman about using .zips with a packaging system similar to Blockland, but not quite close.
I have over 2. something gigs of addons, and the only thing that keeps it stable is Addonmisso,
which is really a mod manager.