Réserve is a short Japanese erotic adventure game with RPG-style combat. The player controls Mio, a young woman who is about to go on a date when she suddenly falls into a portal which transports her to another world. A fairy-like creature tells her that she may be able to return to her world upon reaching a portal in a nearby forest, but she will have to get past all kinds of perverted monsters first.

The player must guide Mio, represented by an icon, through the world map. Occasionally, a monster will appear, which will cause Mio to go into battle mode. In battle mode, the player must guess which parts of the monster will be most effective to attack until it is defeated. Getting two answers wrong in a row will result in a game over screen depicting Mio being molested by the monster in question.

[From Moby Games]