Honestly, this VN doesn't really play up the brother/sister relationship as hard as others. At least for most of the chapters, you could totally interpret their relationship as best friends who are sharing an apartment for college (literal roommates). It isn't until later where there are some cracks in the dialogue that hint at a taboo where the sibling relationship becomes more evident. And then later it's revealed that they were raised together in the same household, so logically they'd have to be step or foster siblings at the very least.
I personally don't care whether or not there is Incest though I trend towards preferring non-incest. It's just so common in VNs that it's practically a rule at this point that hot family members are fuckable. That said, more than anything I like dialogue to work in context though and sometimes incest is specifically NOT intended (like in the case of Origin Story). So usually I'll start a VN with the default dialogue right up until the dialogue doesn't make sense without incest, then I'll toggle it on or get a patch.
Yeah same for me overall... some games are written like incest games all the way, but dont have incest to avoid Patreon ban. But its crystal clear that its incest. Most of the time there is a little i-patch for it, or you can set the relations and everything makes sense.
And than there are games where it jumps around like a horny rabbit... shale hill is one of those. Most of the times MC and Leah are acting just like good friends that attend college and live together. And than there are serious incest vibes. Like growing up together with the same parents in the same house. The whole taboo vibe with their relationship. Or that the MC got money for his illness and gives up the money to buy him and Leah a appartment and pay for college... for the both. You dont do that for a "friend". Its like the DEVs couldnt decide if its incest or not... so it jumps between non-incest and incest back and forth. Overall a somewhat "incest" relationship makes a tiny little bit more sense in Shale Hill to me, but with or without incest doesnt matter, in both ways there are just huge problems.
When a game has incest tag AND patreon, i usually look up if its written as a non-incest game, if not i try to avoid those games for now... sometimes the tag is just there cause someone made a i-patch that doesnt really work well for the game. (where the heart is, is a good example) But if a game is written as incest and just avoids it in a ridiculous way just to stay on patreon, the game is mostly ruined. Good example for a ruined game because of that is Life in Santa county. You cant play it with i-patch anymore cause its a buggy mess where my hair is turning grey and without it is just totally ridiculous nonsense. It gets like that if DEVs dont have a plan to write (or re-write) the game without incest but need to.
So more and more "incest" games are not really enjoyable anymore, but well, looking at my play-history, my favorite games dont have incest in them. Shale Hill is not one of my favorites... it just has way to many flaws. But its still a good one.
