head to head
Neither is simply harder - they are hard in different places. Portal demands more execution; Tropico 5 demands more variance.

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

Optimization · Pure Optimization
Advancing a colonial island through history while optimizing production and appeasing fixed-script factions.
Portal leans Optimization (Pure Optimization); Tropico 5 leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Portal
Portal placement timing modest.
Tropico 5
Interface-driven play with no physical execution ceiling
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.
Tropico 5
Factions and superpowers follow scripted logic
Tropico 5 leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Tropico 5
War outcomes and election swings carry hidden randomness
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.
Tropico 5
Era progression and economic chains reward systematic planning
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.