head to head
Risen 3: Titan Lords asks more than Portal, and the gap is variance.

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

Optimization · Pure Optimization
Build planning and faction routing through a fixed open world with modest combat demands.
Portal leans Optimization (Pure Optimization); Risen 3: Titan Lords leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Portal
Portal placement timing modest.
Risen 3: Titan Lords
Dodge-and-strike combat punishes carelessness moderately
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.
Risen 3: Titan Lords
Monsters and humans run fixed AI routines
Risen 3: Titan Lords leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Risen 3: Titan Lords
World state is scripted; loot variance is minor
Portal leans a little harder on optimization, though the gap is small.
Portal
Pure puzzle-solving optimization.
Risen 3: Titan Lords
Faction choice, build planning and quest routing dominate power
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.