Personally, I like the NPC Sex genre, because it scratchs that itch of wanting to be able to fuck anyone at any time. Its just kinda unfortunate how some of the games made in this genre handle that. Some have just waaay too few npcs you can actually fuck. Some have good variety but get bogged down by poorly optimized maps and bad taste in graphics. Some have fetishes that just take even this too far, like shitting on some chick's face. (looking at you Sex Ticket)
For this one, the 2.5D graphics were novel at first but very quickly became sour when the game ran like ass in any large map. Ironically, the fastest map was the world map. Let's not forget that the body variety of the npcs is actually pretty poor in this too. They're all gigantic tits and asses, or overly chubby if they had smaller than G cup tits. Don't even get me started on strange anus placements. For those that don't know, the anus is about an inch or so away from the vaginal opening... So to see it four to five inches away, where the tailbone would be, is just off putting.
For once I'd like to see a NPC Sex game that really hammers in the fantasy NPC Sex... ness. Like, you can bang every mid age and lower female character as a start, then you find a potion of youth to turn old grannies into hot teens and milfs... Then a genderbender potion that turns male NPCs into female ones. Maybe a humanizing potion that turns animals and monsters into animal girls and monster girls. Make it just a real NPC Sex paradise. That would be awesome... and would be the effective end point of the genre.