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

Optimization · Pure Optimization
Optimizing mecha squad builds and development plans through solvable tactical stages.
Plague Inc. leans Optimization (Pure Optimization); SD Gundam G Generation Cross Rays 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.
Plague Inc.
Tapping menus only
SD Gundam G Generation Cross Rays
Turn-based menus - hands are irrelevant
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
SD Gundam G Generation Cross Rays
Enemy AI follows fixed priorities, never models you
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
SD Gundam G Generation Cross Rays
Hit rolls and crits wobble individual turns slightly
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
SD Gundam G Generation Cross Rays
Squad building, unit development and stage routing 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.