head to head
Neither is simply harder - they are hard in different places. Cube Escape: Paradox demands more variance; Portal demands more execution.

Optimization · Pure Optimization
A surreal escape-room chapter of the Rusty Lake saga where a detective pieces his memory back together.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Cube Escape: Paradox leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Cube Escape: Paradox
Pointing and clicking only; no physical ceiling.
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.
Cube Escape: Paradox
Everything is scripted; nothing models you.
Portal
No adversary modeling player.
Cube Escape: Paradox leans clearly harder on variance.
Cube Escape: Paradox
Cryptic hidden clues dominate first playthrough, then converge.
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.
Cube Escape: Paradox
Fixed puzzle chains in one room are the whole game.
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.