Excellent concept and I get/sorta like the feel of it 'feeling' like an RE game but it does suck in any erotic game to get stuck or for it to 'feel like a grind' (there isn't any grind but getting stuck basically has the same reception). I think this can either be resolved by a 'cheaper' way which is a walkthru that many games have but I do think it'd lose a novelty to it. I do think especially if any kind of sequel were made or if the dev plans on making another game, the more involved but also I think better solution is to make integrate the game's eroticism into the puzzles. This would be a very specific and unique example but anything along the lines of this kind of thing like you enter a toilet stall and find suspicious hole on the outside of the stall, pointing the player to inspect inside the stall where they find like a mess of whatever writings on the walls and stains on the toilet and ground. Then maybe you encounter like a character who had to cut off his dick because it got bitten or something but he's in love with a female zombie of a supermodel/instagram model type and you need to (as a female character) need to find sperm to feed her in order to get the whatever item he has in exchange so then the player thinks about the gloryhole they inspected earlier and think that would be a place where there might be a used condom and lo and behold, they go there and there's a used filled condom with semen she can use to feed the female zombie. If you don't want it to be so direct/easy then you know can have like 2-3 other places where maybe she'd find it like maybe there was a semen bank but it's empty or unusable or something or Bob (whatever character) is the only character she knows who could provide it but he refuses because of how his character is written like maybe Bob is an ascetic or something.
Or a different example maybe you have some idk hole or like certain space that needs to be filled to get a door working or something and earlier the player went thru an abandoned college girl's room where there were among other like actually erotic/interesting things to inspect like maybe sexts or like fetish items hidden in areas or like pictures of the college girl (who is maybe not a zombie and the player might encounter later especially as a male protagonist) and also a drawer full of dildos and there's one in particular that's the one that'd fit the door or something. The important point is not feeling like you're kinda wandering not knowing where to look for the thing you need and instead having somekind of impression of at least where might be a place to look.
I do also think erotic games kinda always run into a problem when the reward system is thru losing/failing. So maybe idk this is a little more idk but maybe something like instead of getting the full scene when losing, instead it's like the full scene is unlocked by like unlocking bonus safes or like yea secret easter eggs to fill a video gallery and when you lose you only get either like the teasing intro or sorta an abridged version or first half of the scene. I also do think on a much more minor note 'you lose' is better than 'you failed'. Even though it's very minor, it fits an erotic game better like when people say 'I lost' when seeing like a particularly exciting look or fetish or whatever.
Or a different example maybe you have some idk hole or like certain space that needs to be filled to get a door working or something and earlier the player went thru an abandoned college girl's room where there were among other like actually erotic/interesting things to inspect like maybe sexts or like fetish items hidden in areas or like pictures of the college girl (who is maybe not a zombie and the player might encounter later especially as a male protagonist) and also a drawer full of dildos and there's one in particular that's the one that'd fit the door or something. The important point is not feeling like you're kinda wandering not knowing where to look for the thing you need and instead having somekind of impression of at least where might be a place to look.
I do also think erotic games kinda always run into a problem when the reward system is thru losing/failing. So maybe idk this is a little more idk but maybe something like instead of getting the full scene when losing, instead it's like the full scene is unlocked by like unlocking bonus safes or like yea secret easter eggs to fill a video gallery and when you lose you only get either like the teasing intro or sorta an abridged version or first half of the scene. I also do think on a much more minor note 'you lose' is better than 'you failed'. Even though it's very minor, it fits an erotic game better like when people say 'I lost' when seeing like a particularly exciting look or fetish or whatever.