Seeking Ataraxia is a choice-based game that describes a couple of ordinary days in the life of a university student who suffers from OCD and anxiety.
The game is a bit buggy and inconsistent in some details, for example the protagonist's apartment keeps reverting overnight from cleaner than it has ever been to total mess, the text talks about an alarm clock's digital display but the illustration shows an old mechanical wind-up clock, and so on. Nothing that couldn't be easily fixed afterwards.
There isn't any mentionable gameplay or plot, but the main goal of these slice-of-life games that describe mental health issues usually differs from other games. Instead of going for entertainment values or explosive action, the goal is often to provide peer support to others diagnosed with the same issues, personal therapy, raising awareness about the symptoms and consequences of mental illnesses, or any combination of them.
Seeking Ataraxia doesn't explicitly tell what its goals are. It's billed only as "a game about anxiety" but it seems to work quite effectively as public education. I certainly learned some things that I didn't previously know about e.g. how OCD can manifest itself. It describes the symptoms personally but neutrally, without preaching or overexplaining. It lets the readers come to their own conclusions about what kind of effect mental health issues have on the protagonist's life.
One problem with mental health issues is that it is often hard to realize that the symptoms might be due to illnesses instead of external causes or personal characteristics. The public service provided by games and other media that accurately represent mental health issues is that they can make people recognize the same symptoms in themselves and seek a diagnose.
It would be interesting to find some data on how effective games like Seeking Ataraxia and Depression Quest are in finding the audience that isn't already aware of the issues they're trying to raise. When a game is purely about the thing it advocates there's risk that it ends up preaching to the choir.
In the best case scenario there's a hook that makes the game attractive to the general audience even when the player don't necessarily actively want to learn about the subject matter. Coming up with such a hook is the hard part though: once you do play the game the effectiveness comes from the relatable everyday setting that would be lost if the plot involved some grand adventure. It might be exciting to play but the credibility of the message would be diminished the farther the plot would deviate from the audience's personal experiences.