Did you try to activate on steam over the bottom left: Add a game?
I just checked, we ran out of steam keys.I requested more on steam, will fill them back up asap.Sorry for the inconvenience.(I will reply to this message again when they are restocked, you can claim it then)
Yay, so that's what's wrong!
Sorry :S
I'm just glad to hear it's a simple fix, thanks for the update! I'll check back later.
Hello again!
We're glad to share that the keys have been restocked. Please try and renew your key again and let us know how it goes.
It went through, the key was provided by itch.io and renewed on Steam with no difficulties!