I've already ruled out Red's initials since I know his name. It's not that. and I figured "Hunter in the World" would seem appropriate for a survival/crafting game but I'm really just taking stabs in the dark. I am also assuming the acronym is German but I could be wrong. "games" in German is spielt so maybe the acronym is English afterall.
Maybe JIW means nothing. I once asked Red what "Red51" means and apparently it was something random he picked for a screen name.