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 · Systems & Chaos
Isolating targets amid randomised crowds using traps and patience.

Optimization · Pure Optimization
Survival horror prequel built on swapping two characters with no item boxes.
Party Hard leans Optimization (Systems & Chaos); Resident Evil 0 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.
Party Hard
Walking and stabbing need timing but little dexterity
Resident Evil 0
Tank-control combat is modestly demanding
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Party Hard
Partygoers wander on RNG, not adaptive minds
Resident Evil 0
Enemies follow fixed behaviour
Party Hard leans a little harder on variance, though the gap is small.
Party Hard
Random traps, events and witness behaviour vary each level
Resident Evil 0
Hidden layouts surprise until mapped
Resident Evil 0 leans a little harder on optimization, though the gap is small.
Party Hard
Trap usage and isolation tactics converge to known strategies
Resident Evil 0
Two-character item juggling makes routing the real 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.