3 Years of Service
I'd say "Grace of the Labyrinth Town", an RPG maker with boring dungeon crawler gameplay and a heroine-corruption mechanic that takes a long time to set up, but is very well brought together, with a rich story and dialogue (perhaps too much, given the type of game). But the quality of the scenes (which are not static!) is incredible, and the game quickly turns to the pregnancy and childbirth theme (the last one is not shown, though). And last but not least, the gallery is huge, and the game lasts just a few hours.
A very pleasant surprise
A very pleasant surprise