Plot-wise Demon Boy resembles traditional incest/supernatural VN. The MC is a guy who is beat by bullys, until he find out a ancient book and summoned a succubus demon and from this point his (sexual) life changes completely.
But if the plot is not new, Demon Boy compensates it delivering quality in all the aspects: the pace is great, you can play and read all 4 chapters in a row without feel tired and/or the time passing. The story is solid and take its time but doesn't drag to introduce the characters, unfold the plot and establish its own lore about the demons, this way everything makes sense, nothing sounds out of the place and we keep interested in knowing more about this universe and other things about the story: the real intentions of the succubus Lilith, why other demons are chasing her and what's the role of MC in all of this.
Demon Boy also nail it in the visual and lewd aspects: the renders are great, high quality and quite erotic, the women models are stunning. Nicole, MC's "landlady" and probaly the main LI, is definitely one of hottest and beautifull MILFs created for a VN in the recent years. Like other games, the incestuos relationship is a slowburn, and very well-made slowburn. Eromersive, the dev of this VN, build-up the sexual tension and erotism scene by scene giving a real sense of progression in the MC/Nicole's relationship.
But while it's a slowburn with the "landlady", with other characters MC can progress way more faster. So players are only "blueballed" in this game if they want it. Maybe the only critique i could make is about the lenght of the lewd/sex scenes being usually shorts depending the number of options available. The point system (love and lust) can make be a bit hard to achive the lewd scenes, but imho can also give a sense of acomplishment that add more satisfation when we succeed.
Overall, Demon Boy is already imho a great VN despite still be in early development with great renders, animations, women models, story, build-up and lewdness.
Edit: Dev reveal to be just another incompetent/scammer wasting everyone's time. Don't bother play, is simply worthless.