Any way to give away a game removed from the Steam Store?

Then maybe in the "Other" Category ? Chronicles of Narnia: Prince Caspian can be given away although it's not on Steam anymore (still no CV though I think)and I vaguely remember it was briefly gone and then got re-added. And aren't there also old versions of Trine Collection, Risen Collection or Hitman Collection (all of them without the newest game) in the Create GA list although they can't be bought on Steam anymore ? I'm writing from my phone right now so I can't look it up properly.

As long as they exist in the database, they can be given away. I am currently having an entry for such a game. You just have to ask support to add it to the giveaway list.

Then again, if the game was free at some point, this all comes moot. :)