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

Optimization · Pure Optimization
Hoenn's definitive version, crowned by the strategy-heavy Battle Frontier.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Pokémon Emerald leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Pokémon Emerald
Turn-based commands only
Portal
Portal placement timing modest.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Pokémon Emerald
Battle Frontier AI is fixed-policy
Portal
No adversary modeling player.
Pokémon Emerald leans clearly harder on variance.
Pokémon Emerald
Encounter RNG and Frontier hax
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.
Pokémon Emerald
EVs, movesets, and Frontier strategy run deep
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.