You'd have to find out a way to "measure" your success. These are written stories, so stealth mechanics may be a bit difficult to turn into a minigame. Luckily, there are variables you can input - such as items, dice rolls, random chance type things. When I think mingame - I think of a system that has different mechanics than the game I am playing, but still based within in. For a CYOA, it would be hard to put in a minigame with that definition because the premise is "your options are A,B, or C" then picking one affects the story.