Consider having it either as a super-secret unlockable thing (100% the rest of the game to unlock it) or as a paid-only DLC (require payment to keep the kids from getting it etc).
That said, unlockable might be better but up to you.
I know you aren't on Discord much but if you were I could do a bit more to help promote your games and offer advice on things I've dealt with in regards to IRL stuff and ways to work around the lemons :P
If you want to flex writing muscles, consider dropping a few drafts on writing-websites and cross-promoting it on your itch pages here. The easiest way would be to have a central website for all your stuff and links and so on so that you wouldn't need to worry about including a Patreon link everywhere. It isn't easy to find :P
Poke me on Discord if you want info on setting up free websites that won't plaster ads all over your page. Something basic will work for now.