We've just added them.
You can grab one from the download page once you claim your purchase.
Where on the download page... I can't find it (:
Crazy cool game by the way! Never even heard of it till I was browsing here on itch... I'll spread the word!
If you claimed the game for free (as per the current special promotion) a Steam key is not available (DRM-free download only) so you have to make an actual purchase to get one, which is totally fine as far as I am concerned.