head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, and it is a single point.

Optimization · Pure Optimization
The definitive Johto adventure, adding animated sprites and the Suicune storyline across two regions.

Optimization · Pure Optimization
Deep empire optimisation over a hidden map against mappable AI.
Pokemon Crystal Version leans Optimization (Pure Optimization); Sid Meier's Civilization IV 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.
Pokemon Crystal Version
Menu-driven battles; zero hands requirement
Sid Meier's Civilization IV
Turn-based clicks have no physical ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Pokemon Crystal Version
Scripted trainers; human link battles are optional
Sid Meier's Civilization IV
Human multiplayer adds diplomacy reads; AI is mappable
Sid Meier's Civilization IV leans a little harder on variance, though the gap is small.
Pokemon Crystal Version
Encounter and catch RNG, shiny odds, crit rolls
Sid Meier's Civilization IV
Map generation and unrevealed terrain drive early decisions
Sid Meier's Civilization IV leans a little harder on optimization, though the gap is small.
Pokemon Crystal Version
Type charts, movesets, and two-region routing dominate
Sid Meier's Civilization IV
Tech paths, tile yields and expansion math dominate outcomes
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.