head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Optimization · Pure Optimization
Physics sandbox about engineering medieval siege machines that usually explode beautifully.

Optimization · Pure Optimization
A physics puzzle game about building wobbly towers and bridges from living goo balls.
Besiege 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.
Besiege
Piloting wobbly contraptions takes some hand skill
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.
Besiege
Static castles and scripted defenders
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.
Besiege
Deterministic physics and fixed objectives
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.
Besiege
Machine engineering is the whole game
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.