Monster Girl Dreams is a text based BFRPG made in Ren'Py. (The BF stands for Battle Fuck.)
The game is currently in alpha and is in active development, and while primarily text based there is character art for many of the lovely ladies in game.
Erotic content contained withing is primarily vanilla, M/F, femdom, and of course monster girls.
In Monster Girl Dreams you play as a male adventurer, freshly graduated from the adventuring school, Adventum!
Now you must venture across the home continent of the monster girls, Lucidia, in an attempt to get rich, or get fucked into submission trying. Also defeat the Demon Queen. Maybe.