I LOVE THIS GAME!!! One of my favorite H-games I've ever played.
The protagonist is a heterosexual (er, mostly...) short-haired tomboy who cross-dresses. Even if you were to let the cross-dressing bit slide, I'm pretty sure that is 100% unique in the world of H-games. Every other cross-dressing female protag in an ecchi game that I've ever heard of is in a yuri story.
There's just a couple ways it could've been better... One, nothing much comes of the whole "cross-dressing" thing. With the exception of the bathhouse scene, everyone in the game world seems to recognize that Sophie is a girl immediately even though she has tiny boobs, short hair, wears male clothing, and works a manly job. I guess that's realistic if they're hearing her talk, but c'mon, they could've done something with it. The closest we seem to get is when she loses a fight to a street thug in the slums and he only notices she's female after knocking her down.
And more importantly... why no pregnancy content, even if it's just an ending (I probably missed some endings, I only got the 1)? Or, considering that it's the fantasy-1800s, at least some more concern about it? One of the early scenes was super hot because Sophie is fretting about the risk of getting pregnant, and I think a few minor antagonists in the cases mention it while banging her, but it seems to quickly taper off and she stops caring. Maybe I need to play all the way through the "gang route"...
Anyway, aside from her looks, my favorite thing about Sophie is how low-key she is about the whole corruption thing. It's so refreshing to see an h-game heroine who doesn't become self-loathing or get 'mind-broken'. Sophie isn't all "Noooo, how can I be enjoying this, I've become a worthless pig slut, I'm ruined forever"." It's great how her spunky, tomboyish attitude stays mostly intact even after she reaches the point where she starts dropping her panties for any guy that asks.
Sadly, I know it's unlikely we'll get a sequel or expansion, but I'm holding out hope that Clymenia or another good creator gives us another game with a tomboy heroine. The cloest to another example I can think of in h-games is "Misty and the Tower of Paradise", and in that case, the heroine is generally quite girly (though more sexually forward than the average hentai heroine), she just happens to have a boyish haircut.