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

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.

Optimization · Pure Optimization
Saturn tactical RPG trilogy whose three scenarios interlock around promotions and party synergy.
Portal leans Optimization (Pure Optimization); Shining Force III leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Portal
Portal placement timing modest.
Shining Force III
Turn-based grid battles only
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Portal
No adversary modeling player.
Shining Force III
Enemy AI follows fixed aggression patterns
Shining Force III leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Shining Force III
Crit rolls and counterattack chance
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Portal
Pure puzzle-solving optimization.
Shining Force III
Promotion timing, friendship system, and positioning are masterable
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.