Because Gmod is a mod, it really doesn't have a rating. But to offer my opinion, it is one of the most successful mods out there in fact it is the mod with the most servers on steam. (If you judge games like CSS as games not mods).
-Hyper Sniper
No. Gmod is only for PC
no. gmod is only for the pc.
You need to download Gmod 9.0.4c when you start there will be 3 choose unmark the Gmod 9.0.4b and your set to go and play gmod 9 online.
Gmod 10 is a pay game. It can be purchased from the Steam store at http://store.steampowered.com It costs $10
you click the shortcut icon er the gmod .exe/file!
go to steam.com here are some links related to Gmod to help you: Steam: http://store.steampowered.com/ Download stuff to Gmod here: http://www.garrysmod.org/downloads/ About Gmod: http://www.garrysmod.com/about/ Gmod fourums: http://www.facepunchstudios.com/
It doesn't really have one, I would say 12+ because it has blood and Zombies.
NO
gmod 9, yes gmod 10-no
Any Source GamePreferably CS:S as most gmod users have this
piggymoo.com has all of stargate, but I'm not sure what gmod is.
steam/steamapps/username/gmod/gmod/data/adv_dup(or something like that)/* *place dupe .txt file or file folder with dups in it, here)