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
Strategy sim about evolving a pathogen to outpace the world's cure effort.

Optimization · Pure Optimization
A small-plot city builder where specialization economics and traffic engineering decide success.
Plague Inc. leans Optimization (Pure Optimization); SimCity (2013) leans Optimization (Pure Optimization).
SimCity (2013) leans a little harder on execution, though the gap is small.
Plague Inc.
Tapping menus only
SimCity (2013)
Mouse planning; no dexterity demands.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Plague Inc.
World response is algorithmic, not adaptive to you
SimCity (2013)
No opponent; multiplayer regions cooperate.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Plague Inc.
Spread events and cure pace fluctuate
SimCity (2013)
Agent simulation quirks behave unpredictably.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Plague Inc.
Evolution-point timing strategies are largely solved
SimCity (2013)
Specialization chains and traffic layouts reward systematic planning.
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.