head to head
Neither is simply harder - they are hard in different places. Breath of Fire IV demands more variance; Portal demands more execution.

Optimization · Pure Optimization
A dual-protagonist JRPG where mastering cross-character fusion and combo optimization resolves all scripted encounters.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Breath of Fire IV leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Breath of Fire IV
Menu combat; combo system has minor sequencing
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.
Breath of Fire IV
No adaptive foes; all patterns are fixed
Portal
No adversary modeling player.
Breath of Fire IV leans clearly harder on variance.
Breath of Fire IV
Random encounter variance and some enemy action randomness present
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.
Breath of Fire IV
Cross-Ryu fusion, combo chains, and AP economy are the solvable layer
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.