There's Quest RPG. It's a simple system that's meant to be an introduction for RPGs in general. They do the degrees of success thing with a d20. I looked into it as a lighter, more story focused alternative to 5e and used the dice roll mechanic to run an improvised game for my kid niece and nephew that went pretty well.
There's also a mech game called Salvage Union that uses the same system. Don't know if there are any others.