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

Optimization · Pure Optimization
A physics puzzle game about placing objects to solve spatial challenges.

Optimization · Pure Optimization
A physics puzzle game about building wobbly towers and bridges from living goo balls.
Create leans Optimization (Pure Optimization); World of Goo leans Optimization (Pure Optimization).
World of Goo leans a little harder on execution, though the gap is small.
Create
Placing objects has no timing demand
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.
Create
No adaptive opponent
World of Goo
No opponent exists
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Create
Physics deterministic and predictable
World of Goo
Physics are visible and deterministic
World of Goo leans a little harder on optimization, though the gap is small.
Create
Finding object placements that solve spatial puzzles is the loop
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.