That was a really nice read. Thanks manI have to agree on the point of sandbox games. It's better to reserve that kind of thing for games with actual gameplay outside of lewd things like many other games do. Say what you will about RPGM or Unity or Unreal but while some of the worst games use those engines they also are used by some of the best games. I will emphasize this one trait of yours I see though, you care a lot more about world building then some people. I really found myself wanting a sequel or prequel or even a spinoff because I just wanted to see and learn more about this world. The characters did come off as same-y a fair bit of a time and it would have been nice to have them show a few more personality traits that make them unique even if similar. Still even with it's flaws this was awesome.
I wanted this to be longer than it was but at the same time I kind of want to see new adventures of these people. Cressa is learning to control her powers and that could make for a great story and fantastic RPG like game where you basically manage her time to make her as powerful and skilled as possible. Aymee learns to take charge but can she master the skills she was shown? Where do her military campaigns take her? Does she start her own mercenary company and part with her commander to prove herself out in the world and become like the MC in this game? Could make a damn good strategy/tactics RPG lite game. What about a full on RPG for the elven knight you help?
I'll state it plainly. This is more of the beginnings of an IP than a standalone adult novel. If you keep working at this in your free time it could easily make it to the market as a non Japanese adult game IP. The animations, lack of censors on genitalia and more realistic look would make this game and any more you make based on the world really stand out in the adult games market. I think this is worth pursuing as a real long term project.
It might not make you rich but it could make you a living. My suggestion is to shore up your weak spots first. Look into practicing writing characters by writing short stories and start thinking "Why is this in my game?" when adding any feature. This will prevent useless sandbox or unnecessary grinding elements.
I will end this long winded tirade of a post with a small story. I made an adventure based off of this game's setting and lore. It's short and only one character from the game makes an appearance when you meet with a merchant at the market and suddenly decide to get something to eat. My group loved the blue haired vendor and were incredibly interested in the setting. One player was visibly disappointed when I had to explain to them that there was no more to the setting as I am not it's creator. I merely borrowed it to make an adventure that I might see if my gut instinct on it's value was right. So to cap this off I'm going to quote my players. Please note the Englishman has a very informal manner of speaking among friends and pardon his French.
"You bitch. Get your ass to wherever you found this creator and tell him to get off his lazy ass and make more shit. I want to travel to the damned empire!" ~ Daniel
"Wait you said this came from an adult game? So it's got an actual game worthy setting even though it has adult content?" ~ Vincent
"It's not every day you see interesting religions in any setting. They tend to follow a certain mythos or set of rules. I really liked how these strange priests worked. Were they death priests or something?" ~ Linus
"Damn that explosion with the magical ore...crystal...whatever it was, was freaking awesome. I can't believe that the game had a similar moment where it was used to power a massive spell that wiped out an army." ~ John
The entire group looks forward to the day they can continue the adventures of, "We R' Us, Creative Solutions Mercenary Company".