head to head
Neither is simply harder - they are hard in different places. Pokemon Sun demands more variance; Portal demands more execution.

Optimization · Pure Optimization
An Alolan island-trial reinvention of the Pokemon formula that swaps gyms for totem battles.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Pokemon Sun leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Pokemon Sun
Turn-based menus only
Portal
Portal placement timing modest.
Pokemon Sun leans clearly harder on reads.
Pokemon Sun
Totem battles are scripted, not adaptive
Portal
No adversary modeling player.
Pokemon Sun leans clearly harder on variance.
Pokemon Sun
SOS calls, encounters, and catch rolls add luck
Portal
Deterministic chambers; no randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Pokemon Sun
Trial puzzles and team matchups carry the game
Portal
Pure puzzle-solving optimization.
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.