Free on Steam: https://store.steampowered.com/app/787340/A_Hat_in_Time__Seal_the_Deal/

A note, I don't know if you can grab it if you don't have the base game. I tried grabbing it, but it gives me an error. Not sure if it's due to me not having it or if it's a problem on Steam's end. Other game DLCs that I've posted don't require the base game to grab so I'm unsure.

Man, this bugs me so much. Literally the entire selling point of this game for me was that they promised free expansions as part of their kickstarter campaign. Time limited, although technically not going against what they said, is pretty scummy, IMO. Oh well, thanks for calling it out, you actually reminded me to grab it today.

Yeah it doesn't work unless you have the base game, thank you for letting us know anyway!