Single-player contents are available in the game. What I mentioned in the last post is an additional mode as I've been keeping adding new content in the past years. But no worries mate. You can contact Itch to arrange a refind as in this post. https://itch.io/t/706742/how-to-get-refund
I can't directly handle it on my end, but please let me know if there's a problem in the refund process and I'll help you with it.
Cheers!