There are a few posts on GoGoBundle's site about keys for this game being revoked, which I found after discovering a key I got from Indiegala several months ago shows as duplicate despite never being used, so it appears this is a widespread issue. @Digital Bento: are you aware of this, and is it possible for those whose keys have been revoked to get replacements?

Hi, message me privately with your key and I can get you a replacement one. Some of the unclaimed keys were deactivated cause one of my bundle partner hasn’t paid me for bundle sales.