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 sandbox city builder that is pure traffic and zoning optimization.

Optimization · Pure Optimization
Pure factory-layout optimization with no pressure, randomness or opponent.
Cities: Skylines leans Optimization (Pure Optimization); Shapez leans Optimization (Pure Optimization).
Shapez leans a little harder on execution, though the gap is small.
Cities: Skylines
No reflex demands at all.
Shapez
Placing belts has no time pressure at all
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Cities: Skylines
No adaptive opponent exists in the sandbox.
Shapez
No adversary exists anywhere
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Cities: Skylines
Minor disaster events if enabled.
Shapez
The infinite map's shapes are mappable immediately
Cities: Skylines leans a little harder on optimization, though the gap is small.
Cities: Skylines
Traffic flow, zoning, and budgets are fully solvable.
Shapez
Designing efficient cutting and merging factories IS the game
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.