Remember those Fighting Fantasy gamebooks, which were like big choose your own adventure games with a character sheet and some roleplaying elements? There’s a full RPG available based on those books called Advanced Fighting Fantasy. It has a simple, streamlined system with an old-school feel and is a great alternative for those looking for a system that’s a little more old-school and retro but want to try something that’s not just based on D&D.
You can checkout the quickstart for free here. It comes with the basic rules of the game as well as a sample adventure.