Dynamo is a simple, narrative-heavy superhero system that started as my 2013 NaGaDeMon project. It's meant to be played as a light-hearted take on golden age superheroes. The game plays with little preparation on the part of the GM.
designer's blog comment:
Originally, the Dynamo rules document was a two-page slapdash thing that introduced character creation and the basics of game play. Unfortunately, while that was fun to put together, unless your game consists almost entirely of players telling each other stories that short of a document doesn't cover enough. There were a few topics that people who played with the brief rules wanted clarification on. …
So I've gone back to the drawing board and, returning to the golden age inspirations I called on before, I redesigned and expanded the rules document. I've padded out the text to get away from the vague hand-waving and include some actual rulings on different behaviors. It's still a pretty lite system, but I think it's more solid and playable now.