I want to try out the patron ver of succubus stories, but would I need to keep the subscribe to gain access to the game, or is it an one time buy?
Sort of both. You get access to the game at the time you become a patron and can redownload it as much as you want for as long as you remain a patron, and you can keep the game files you have downloaded, but if you’re not a patron anymore in the future and there’s an update, you won’t get access to the new version since you’re not a patron anymore. That said, development has slowed a bit, so updates will be less frequent (1-2 per year for the next few years is the plan). Does that make sense?
With the web version, since you don’t download anything, though, you do need to remain a patron to gain continual access to the patron edition of it.
You can also buy the game on Steam. That version is sort of a halfway point between the patron and free editions in terms of features, but you will gain permanent access to the game and all future updates. Here’s the breakdown on the wiki: https://outsiderartisan.miraheze.org/wiki/Editions