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
Plannable type-matchup progression through two regions of fixed trainers.

Optimization · Pure Optimization
A farm-life sim solved by season routing and profit optimization.
Pokémon SoulSilver Version leans Optimization (Pure Optimization); Stardew Valley leans Optimization (Pure Optimization).
Stardew Valley leans a little harder on execution, though the gap is small.
Pokémon SoulSilver Version
Menu-driven battles have no physical component
Stardew Valley
Trivial timing on fishing and combat
Pokémon SoulSilver Version leans a little harder on reads, though the gap is small.
Pokémon SoulSilver Version
Trainer AI is scripted; human battles are an optional sideline
Stardew Valley
No adaptive opponent exists
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Pokémon SoulSilver Version
Catch rates, crits and encounters are bounded randomness
Stardew Valley
Crop luck and geode RNG matter modestly
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Pokémon SoulSilver Version
Team building against known gyms is fully plannable
Stardew Valley
Routing seasons, profit loops, and bundles dominates
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.