Corruption of Champions (customisation of player character)
Trials in Tainted Space (customisation of player character, similar navigation mechanics)
Lust Doll Plus (customisation of player character at start, limited customisation after)
Broken Dreams Correctional Center (customisation of player character at start, limited customisation after, similar navigation mechanics)
They're all 'sandbox' RPGs with combat mechanics, too.
None of them have the same level of freedom with the sex scene interactions, favouring written scenes instead (whether this is better is up to individual taste - personally, I like both approaches for their own merits).
There really isn't another game that's exactly like this, but those are the games that have the most in common with it (as far as I know).
(Also probably Corruption of Champions 2, which by all accounts has the same similarities to this game as Trials in Tainted Space does. I've had a hard time trying to get into that one, though, so I can't say so for myself.)