Have you ever heard of Complete Control: Character Design for the Uninhibited?
Well, if you haven't, it's D&D where every component of your character is bought with accumulated XP. You buy each feat, each saving throw increase, every spell slot and constant power.
And if you have, well, I'm recruiting for a game that uses it!

The recruitment thread is here. Not much in the way of story so far, but it's a work in progress.
It's a mid- to low-magic setting. You are the great grand children of the settlers of a daring, dangerous, newly-discovered continent. Your ancestors came on longboats and found various indigenous, native races with little to no advanced technology (irrigation, crops, buildings, etc). Over the last few decades, two cities have sprung up; Vedelik and Varava. They were originally governed by the same ruling family, but have now been separated officially. There is still over 80% of the continent that has been left unexplored.

You will play as descendants of the original explorers, indigenous-tribesmen-turned-guides, or a half-breed between the two. You start with 2600xp to purchase abilities up to 3rd level.