Not accepting correct steam credentials on linking steam account! :-(
You should put your username (Rebellion ID) and password being used to register REBELLION into Steam username and password…
BUT, in my case Rebellion never give me any notification about username or Rebellion ID, not like usual when we registering in GOG or HumbleBundle, instead showing “Come back soon for improved access to your Rebellion Account”, so I can’t continue claim my free game from Steam…
So, when the giveaway period finish and I still unable to claim my free game, I will abandon Rebellion at all…