From the preview at http://www.vagrantworkshop.com/files/preview_ed_age_of_legend.pdf:
This storygame is based on the FU game engine by Nathan Russell.
What you will find in the Age of Legend is first and foremost an easy
game. It is intended as a lightweight alternative to Earthdawn’s own
Step System (which has been around in in various editions since 1992).
Setting and character creation in the Age of Legend is fairly quick
and intuitive, allowing you to play powerful adepts in this ancient
era of heroes, and the game system itself is easy to learn and very
simple to use.
Basically, the Age of Legend is an alternative way to play in the Earthdawn setting, one which eschews the original core mechanic and is intended for "those who want a simple and story-oriented game system" in place of the more complicated Step System that Earthdawn uses. It still offers rules for advancement and a variety of power levels, and one of its focuses is to be played at conventions and with novice players.
Now, I'm just working off the preview of the book here, so I might be wrong, but the Age of Legend seems to take a more heroic tone than Earthdawn does: where I'd describe Earthdawn as having more of a grim tone. Some of this might be my personal impressions.