It could be a nice harem game, but in this case I see no reason for it to be brothel game. Because half of female characters are still "oirans" - so it doesn't really feel as a harem game. Even if game makes sure that you know that mc took virginity of almost all "oirans".
It could be "geisha (don't sleep with customers)" establisent management game. Management minigame (in it's current form) wouldn't suffer as it could simply be redirected to dancing, poetry and other similar skills training. Entertaiment profits could be "connected" to those skill levels. And MC can still play around with everyone and geishas could be viable LI characters.
Or it needs more brothel "content" (at least for the minigame part)
It's still high quality game, though. So it will be worth to go through it, when it will be complete