Ran a solo game of 1st edition AD&D using Mythic. Game went like this:

1. Party enters dungeon, they're supposed to locate a bad villain and distract him long enough for the town militia to thwart his forces.
2. Party encounters a heavy wooden door that's stuck (not locked just stuck). Dwarven fighter steps up and kicks down the door.
3. Giant centipedes behind the door surprise the party and promptly swarm them, killing the party off with their venomous bite attacks within just 2 rounds.
4. ??? TPK ???

Honestly, even though my entire party literally died within the first 20 minutes of playing, I still had a blast and am gearing up to run more games. Mythic is system agnostic but I like old school D&D which is why I chose to run it. This book is an absolute must-have for anyone serious about running solo games or GM-less games.