I'm using it quite successfully for an extended single character solo campaign. I use a Once Upon a Time deck for NPC/location ideas. I've also used Untold to structure sessions. Depends on my mood!
The demo file here on itch has the basics of the system. (It's also on DriveThru.)
Here's a quick rundown from the Introduction:
Traits
Wanderers have two types of numbered traits: Identities and Qualities.
Your character has three Identity pairs, such as Patience and Cunning. These increase or decrease slowly; in a single session, you’ll probably have only one or two Identity changes. Within each pair, the Identities are opposed. Identities are rated from 0 to 5 dots, but a pair can’t add up to more than 7. If an event would increase a pair over that threshold, it instead subtracts from the opposite Identity of the one that’s increasing.
Each Identity pair has two pairs of opposed Qualities, such as Generosity and Selfishness. Qualities increase or decrease more frequently than Identities. Like Identities, each Quality in a pair is rated from 0 to 5, and like Identities, the total for each pair must be no greater than 7.
Traits can slide (move dots from a trait to its opposite), improve (add dots to the trait without changing its opposite), or suffer loss (remove dots from the trait without affecting its opposite).
Rolling Dice
When your wanderer takes action and the outcome is in doubt, you roll a number of 10-sided dice (d10s). How many dice is determined by the sum of one of your character’s Identities and one of their Qualities, and will usually be between 3 and 10.
After rolling, you split the dice into sets based on the number showing on each die. (Sets of 1 die don’t count.) The number showing is the Height of the set, while the number of matching dice is called the Width. For example, a set of two dice showing four has a Width of 2 and a Height of 4.
Failure: If you get no sets, you don’t get what you want. You may be unable to complete the task, or something more pressing interrupts you as you try.
Success: If you get any sets, you succeed and get what you want.
Complicated Success: If you get only sets with lower Height than the Tension, you get what you want, but there’s a catch. (See Tension, below.)
Critical Success: If you get any set with a Height of exactly 10, you get what you want, and something extra.
Tension
If you aren’t rolling against someone who can actively oppose you, you check your sets against the Tension, a number which drives dramatic pacing. If your Highest set is higher than or equal to the Tension, you succeed without complications. If your Highest set is lower than the Tension, you get what you want, but there’s a complication or a new problem presents itself. The Tension goes up by 1 with uncomplicated success, down by 1 with a complicated success, and down by 2 with a failure.