I have three words for this one - Only. In. Japan. Seriously - I love some of the games they get and this one is no different. Konami have recently announced "Project Loveplus".
Project Loveplus is a dating simulator which is 3D-capable, but that's not it's selling point. It's selling point would be the "boyfriend lock" which uses facial recognition to prevent any "virtual cheating". If someone else picks up your 3DS and tries to play the game, your virtual girlfriend (yeah, that sounds normal) will act confused and ask "who are you".