If you guessed any kind of game at all, sorry. If you correctly identified that as a trick question, then you win at DS fandom. That's right, the DS Lite is getting an official camera peripheral, and the first piece of software to use it is Otona no DS Kao Training (Adults' DS Face Training.) In fact, the camera is called the Facening Scan, leaving no question as to its intended use.
What's Facening, you may ask? Well, it's a regimen of facial stretching designed to reduce wrinkles and sagging, and to make your face appear smaller.
The camera is included with the software, as is a DS Lite stand. You bring your own ridiculous face-- you probably already got your first lesson in Facening when you read about this piece of software!