I played a videogame about Monster Girls, you can found it on Steam or author's website (Suits & Sandals), and it is free. I'm talking about Khimera: Destroy all Monster Girls, a beat'em'up-platforming game where you play as Chelshia, chimera girl made in a lab who have to save her island by a band of looting pirates. Anyway, it's not an eroge game.
The game is pretty cute, and I suggest you to play it ;)