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

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

Optimization · Pure Optimization
Untangling surreal fixed puzzle chains room by macabre room.
Portal leans Optimization (Pure Optimization); Rusty Lake Hotel leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Portal
Portal placement timing modest.
Rusty Lake Hotel
Pointing and clicking - no dexterity involved
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.
Rusty Lake Hotel
No opponents, only macabre puzzle rooms
Rusty Lake Hotel leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Rusty Lake Hotel
Solutions are hidden until discovered, then fixed
Portal leans clearly harder on optimization.
Portal
Pure puzzle-solving optimization.
Rusty Lake Hotel
Chaining surreal puzzle logic per room is the whole game
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.