Depression Quest is an ambitious Twine game released today. It is an IF game that seeks to communicate what it is like living with depression, in order both for those who suffer from it to know they are not alone, and for those who do not to have greater understanding of the condition. The game begins with a more in-depth description of its goals, which I recommend reading before deciding whether or not to play, since the subject matter is potentially triggering.
The game is under a “Pay what you want” model: you can play for free or choose to donate any amount you wish. A portion of the proceeds go to iFred.
You can read more about the game in this GameSpot piece by Carolyn Petit.