Adult PC Game: Melly’s Futanari Island (uncen-eng) by Toffi-sama Archive

A very simple side-scrolling game. Your character (shemale) is standing still, and various monsters are approaching him. There are three buttons at your disposal: "a", "s", "d". Each button initiates a rock throw, but at a different height.
If the monster is not knocked down by a stone, he rapes you, after the third rape you lose. The rape scene is shown in full screen mode, there is some analogy with "Dangerous Dave" (not erotica and not porn), where the death scenes were shown enlarged.

Melly’s Futanari Island (uncen-eng) by Toffi-sama Gameplay Preview