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
Puzzle sequel where glove powers paint blocks to solve physical room logic.

Optimization · Pure Optimization
A physics puzzle game about building wobbly towers and bridges from living goo balls.
Q.U.B.E. 2 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.
Q.U.B.E. 2
Occasional timing on moving blocks only
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.
Q.U.B.E. 2
No adaptive element exists
World of Goo
No opponent exists
World of Goo leans a little harder on variance, though the gap is small.
Q.U.B.E. 2
Deterministic puzzles with full information
World of Goo
Physics are visible and deterministic
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Q.U.B.E. 2
Glove-power combinations resolve to clean solutions
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.