head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, and it is a single point.

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

Optimization · Pure Optimization
A physics puzzle-platformer about swapping three heroes to improvise solutions.
Portal leans Optimization (Pure Optimization); Trine 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.
Trine
Physics platforming and wizard-box stacking need dexterity
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.
Trine
No opponent; puzzles are fixed
Trine leans a little harder on variance, though the gap is small.
Portal
Deterministic chambers; no randomness.
Trine
Levels are static and fully visible
Portal leans a little harder on optimization, though the gap is small.
Portal
Pure puzzle-solving optimization.
Trine
Choosing the right hero and contraption solves each obstacle
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.