head to head
SpaceChem asks more than Cities: Skylines, and the gap is execution.

Optimization · Pure Optimization
A sandbox city builder that is pure traffic and zoning optimization.

Optimization · Pure Optimization
A hardcore programming-in-disguise puzzle where you wire atomic assembly lines to synthesize compounds.
Cities: Skylines leans Optimization (Pure Optimization); SpaceChem leans Optimization (Pure Optimization).
SpaceChem leans clearly harder on execution.
Cities: Skylines
No reflex demands at all.
SpaceChem
Drawing waldo paths requires no physical precision
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.
SpaceChem
No opponent; pure logic construction
Cities: Skylines leans a little harder on variance, though the gap is small.
Cities: Skylines
Minor disaster events if enabled.
SpaceChem
All reactor inputs are deterministic and fixed
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Cities: Skylines
Traffic flow, zoning, and budgets are fully solvable.
SpaceChem
Designing correct chemical pipelines that transform inputs to outputs exactly
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.