The whole thing feels like a creepypasta that someone decided to add tits to, and I mean that as a compliment I think. You got this brother who vanished for nine years, right? Nine. And then dad just drags him back home like a stray cat. The sister is all grown up now, with the kind of body that makes you forget the family tree for a second. Big tits, big ass, the 3DCG models are unpolished in that specific way where the skin looks a bit like wax but the proportions are dialed in for maximum degeneracy.
I spent way too long in the investigation bits just clicking on her bedroom door hoping for a panty shot. The mystery is actually trying, there's a paranormal edge and some graphic violence that made me alt-tab once because the sound design got nasty. But then you're back to staring at your sister's chest while she talks about how scared she is. The tonal whiplash is insane. One minute you're uncovering a secret about a crime scene, the next you're a virgin male protagonist getting a boner because she leaned over. It's like the game can't decide if it wants to be Silent Hill or a nukige.
The romance path with the sister is... look, it's there. It's the whole point for most people. The family angle is fucked up and the game knows it, but it also renders her ass in loving detail during every serious conversation. I wish the mystery didn't drag so hard in the middle, there's a whole section about old school records that felt like homework. But then you get a scene where she's in a towel and suddenly I'm a patient detective again. The brother's secret is genuinely disturbing when it finally drops, even if the reveal is sandwiched between two very gratuitous shower renders. Don't expect closure though, the ending I got felt like a wet fart.