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
Deterministic physics puzzles solved by reasoning about magnetism and gravity.

Optimization · Pure Optimization
A physics puzzle game about building wobbly towers and bridges from living goo balls.
Relicta 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.
Relicta
Walking between switches; timing rarely matters
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.
Relicta
No adversary in the puzzle chambers
World of Goo
No opponent exists
World of Goo leans a little harder on variance, though the gap is small.
Relicta
Every chamber is fully visible and deterministic
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.
Relicta
Magnetism-gravity logic chains are the entire 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.