I would be interested in that
OK, so here I go:
I posit that 5e put more effort into 'looking' like D&D instead of really learning from its ancestor editions.
Classes:
WWN has 4 primary classes: Mage, Expert, and Warrior. There is also Adventurer that allows you to mix two class aspects together (but each aspect is weaker than a focused class).
Class Features & Edges:Base class features are mostly minimalistic but effective. Mostly things you get at level 1 and have a simple scale. Everybody has access to a feat-like system called Foci . Foci are significant and are never 3e-style feat trees, usually having a base function, and then an upgraded function. This means that Foci are not optional like in 5e, but it also means classes are simpler affairs without twiddly useless crossover abilities like in 5e as well.
If you want a 'Rogue', you can just be a Warrior or Expert with the Assasin Foci (or a mix of the two with Adventurer). No need to mess around with 8 classes to replicate specific character expressions.
Levels, Skills, & MathsThere are only 10 levels, but it's compressed more value into said levels. Outside of attack rolls, the system uses a 2d6 system for its skill rolls, which makes smaller values much more meaningful.
In place of a +2->6 for a single skill over 20 ****ing levels, you can upgrade a skill from 0->+4 over the course of 10, which has WAY more significance mathematically. There are Edges that also give buffs as well.
Attributes also only range from -2 to +2, but again with the bounded nature of a 2d6 its much more significant then the range of -4->+4
Oh yeah, there is a skill system with skill points. It's not complicated like in 3e D&D. The Expert gets more skill points.
MagicMagic spell categories have been compressed from 1->9 to 1->5 (so Spells of slot 1-2 in 5e are just category 1 in WWN). Magic has been rebalanced (to address the caster dominance that still exists in 5e) by just more specifically custom spell lists that don't exist to be a solution to every kind of problem.
Saving throws follow the scaling systems of 2AD&D, instead of the equal scaling of 3e. There are still only 3 saves.
Mages also have only 1 spell slot category, they just can use those slots for higher-level spells as they level up. So a Mage goes from 1->5 spell slots over 10 levels. Spells are always very powerful, so each spell slot is generally significant.
However, as this is a Harsh nerf, to give mages something else to do, they get a pool of Effort which is separate from slots. Effort is committed to lesser effects (like blasting cantrips, sense magic, counterspells, etc). Depending on the effect, effort comes back faster or slower. Weak effects (like say in combat blast attacks) allow their committed effort to return instantly. Medium effects return after the end of the encounter while more powerful effects only return after a days rest.
There is also very good advice for adding your own spells, but the existing spell lists are pretty good.
I have other stuff to add but I think im running out of space.