RPG

I have tried it, and it's fun while it lasts! I found it very hard to keep my players engaged with the asynchronous sideplay aspect of it.

The experience actually got me to try writing up a set of generic RPG rules that would facilitate asynchronous play better than traditional rules (do a thing, wait, GM tells you to roll, wait, you roll, wait, gm describes the outcome, wait, and finally you can continue). Sadly I didn't really get anywhere productive with them.

I think that if you have players who are into the concept, and keep interactions that require GM arbitration to a minimum, you could have some success with it.