The Donsol rules to play with a standard deck of cards can be found here, and a gameplay video tutorial here.
The game was released for Mobile back in 2016, and re-released for Desktop in 2017 as Hundred Rabbits. While the game was designed on a train, without internet connection, it seems like Donsol's gameplay accidentally ended up being a twist to Zach Gage and Kurt Bieg's Scoundrel, designed in 2011.
Released a new Donsol build, with improved UI and entirely redesigned vector graphics working on all platforms.
Here's the upcoming Donsol build running on iPhone.