I didn't really enjoy this.
Mostly because there's no real explanation. Sure, it's a fairly simple game, but as little information as how much stamina might be gained or lost on a successful roll would help a lot. Or who would gain or lose it. Or if there is a cost to passing. Or if there is a goal or you're just playing to see how far you get. And, for someone whose first difficulty was is a 12, how many dice you're rolling would have also been great to know.