"1 Steam key" simply means that one of the 5 games in the bundle was including the Steam key. I was not one of those 5, as I had turned off that functionality during that bundle period.
However, I am happy to make this right for you. Please reach out to me at support@droosk.com so I can get you a key. I do feel bad about the confusion and the way Itch presented the bundle to you, so I'll do the right thing!
-Droosk