It's not written to be played solo, but you can definitely do character/setting creation solo - I'd definitely be curious to hear about your experience of it if you try it solo!
It was really fun! A lot of the features, for instance the secret cards, don't work very well without multiple players. But I enjoyed the character creation and interacting with the world for a while. The setting is really well thought out. I would recommend it for anyone whether they have a group or not and will play it again if I find the right group.
Thank you for the great game Ari!