Dirty Business is the pilot episode of a nsfw VN series.
The player asumes the role of Velasco, a ex-cop struggling as a private eye, he'll have the help of all kind of women to help him investigate cases (and also could help in other... more personal matters). Be advised: It's a dark and sleazy setting that depicts prostitution, drugs, alcohol, foul language...
On top of the classic VN mechanics (in comic style), there are other elements of gameplay: map, quests, puzzles, minigames...
The series, as a whole, is currently on hold, but the pilot as a standalone game (~ 1 hour of gameplay) works well enough to be enjoyed on its own.
You can check it out and download (for free) in its game page: