head to head
Party Hard 2 asks more than Portal, and the gap is variance.

Optimization · Pure Optimization
Planning stealth kill sequences around shuffled NPC routines.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Party Hard 2 leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans a little harder on execution, though the gap is small.
Party Hard 2
Timing kills matters, but pace is deliberate
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.
Party Hard 2
Partygoer AI is randomized patterns, not adaptive minds
Portal
No adversary modeling player.
Party Hard 2 leans clearly harder on variance.
Party Hard 2
Level item spawns and NPC routes shuffle per attempt
Portal
Deterministic chambers; no randomness.
Portal leans a little harder on optimization, though the gap is small.
Party Hard 2
Sequencing kills, traps and escapes is the actual puzzle
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.