There are many games already, made for many reasons: insofar as this could work, it almost certainly already has.
Strengthens neural circuits involved in developing/maintaining positive habits
That's any game where grinding makes your character(s) stronger, or where progression is gated behind the player learning new skills. (I'm pretty sure Pokemon did exactly this for me as a child.)
Build any sort of positive habits that transfer to real life decision making
That's any strategy game. (I'm thinking particularly of XCOM:EU, with its famously 'unfair' - i.e. not-rigged-in-the-player's-favor - hit probabilities.)
I do think that there are untapped possibilities in this space - I wouldn't have made all those educational games if I didn't - but what you're describing as possibly-impossible seems pretty mundane and familiar to me. (Kudos for considering the possibility in the first place, though.)
I was wondering if something could be designed that's almost as simple as pulling a lever, you can do as many times as you want, and not anywhere near as addictive as ordinary games. And by activating the circuit would strengthen it measurably. My intuition tells me no, but if it is possible some way, I think that would be a game changer
Now I wonder if a video, or a song, etc could do it. Or a writing/reading task. Something low complexity, repeatable, non-addictive, non-time consuming.
You could give it to an alcoholoc at a low price, they could use it 5 minutes a day instead of spending a fortune on therapy. (It's starting to sound like meditation)
I think it's meditation
I wonder if anyone on the forum could share their thoughts on whether it's scientifically possible to develop a video game/app which
Like a virtual morality/discipline gym. Is it impossible or could it work?