Hi there! Thanks for reaching out.

I just checked the thread here on SG for the bundle this game was in and it looks like this is some mistake on Steam's part:
https://www.steamgifts.com/discussion/wwJKW/indiegala-patriotic-detective-bundle

Note: The key for Return of Red Riding Hood Enhanced Edition also includes Non-Linear Text Quests - Return of Red Riding Hood Enhanced Edition which is a DLC for a different game: Non-Linear Text Quests, namely

You will need to first activate Non-Linear Text Quests (free on the store) in order to redeem this key.

A more detailed explanation in this comment and its following ones:
https://www.steamgifts.com/go/comment/WaXMJKY

Could you be bothered to follow the steps provided in the comment I linked? It will then not only activate the game you have won, but also a DLC for it.t

Sorry for the trouble. Had I known beforehand, I had not bothered to make a giveaway for this game :'(