What a banger of a little game. I don't think it's too difficult, although some further hints (i.e. "statue fragments de-corrupted are cumulative", "customers served are cumulative") somewhere would be nice. I stressed out the first time when I thought "how in the heck am I going to get all of them in one run." Once you know a few things the difficulty is much less. The only part I found a little brutal was trying to locate the last statue fragment on the later levels. I think the main thing here isn't the size of the map of the length of the furthest walk, so you could make it a little more of a labyrinth and shorten some of the paths by interconnecting them a bit.
There's also a bug in the treasure hunt level where when it is your companion's turn -- sometimes it glitches and the animation for grab only displays a very short time and you pretty much have unlimited chances to struggle and never get any more than the minimal amount of "lewdness."
I like that the h-content is essential to the game, and I think the gameplay is simple and straightforward enough to facilitate it (the whole point of the game!) The third extra level is pretty ingenious in execution, it legit raised my blood pressure the first time.
If I had a general comment beyond what I've seen here it's that I'd like to know if the corruption does anything gameplay wise other than potentially give you a bonus scene? I never made an effort to avoid corruption, but if 3+ corruption causes some kind of involuntary h-scenes that you have to struggle out of -- perhaps when she is standing still -- that might be motivation to watch corruption more.
EDIT:
I do have to ask though, why the obsession with dark skinned men?
I didn't interpret it this way at all, they're shadows, not africans (or soot-covered rogue steamfitters) -- there's something about the saturation level that makes them look like they are in shadow. I interpret them as the player, the manifestation of his id...