I said in dat other thread in the HCB
Nutaku ain't da only playa in Hentai business but the main one in these Hentai gacha online games, I dont' see anyone in dat role
Manga Gamer does license and distribute physical and digital uncensored Hentai games - bit of overlap w/ Nutaku since they do downloadable games from Japan and Patreon or whatever they find American Hentai stuf
Games of Desire does full on Hentai games - you can't make kiddy versions of these kids, no Gacha - not likely a threat to Nutaku
Zone Sama - another Rules 34 (ugh Americans can't even think up their own original work and do porn parodies - not a threat to Nutaku
for now, there is no other place besides DMM and Nutaku to play these games
been a customer for all these guys before I moved on to Nutaku and then DMM -