head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, and it is a single point.

Optimization · Pure Optimization
A lemmings-style puzzle series testing deterministic route planning for marching minis.

Optimization · Pure Optimization
A physics puzzle game about building wobbly towers and bridges from living goo balls.
Mario vs. Donkey Kong: Tipping Stars leans Optimization (Pure Optimization); World of Goo leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Mario vs. Donkey Kong: Tipping Stars
Stylus rib-placement under mild time pressure
World of Goo
Placing goo balls needs only mild precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Mario vs. Donkey Kong: Tipping Stars
Minis follow strict lemming-like movement rules
World of Goo
No opponent exists
World of Goo leans a little harder on variance, though the gap is small.
Mario vs. Donkey Kong: Tipping Stars
Puzzles are fully deterministic and visible
World of Goo
Physics are visible and deterministic
World of Goo leans a little harder on optimization, though the gap is small.
Mario vs. Donkey Kong: Tipping Stars
Routing minis to the door efficiently is the whole test
World of Goo
Tower structure and goo economy are solvable per level
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.