best solo rpg! it has lite rules and makes use of narrative playing. No pre-written path. The system helps you to develop your own story. The engine is you.
But not only solo. Having the option to play without a GM is also great.
If you look for narrative RPG (not miniatures on a grid but theatre of mind) look no further.
Thank you Shawn for this gem (and for bringing back roleplaying into my life)!