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

Optimization · Pure Optimization
Survival horror prequel built on swapping two characters with no item boxes.

Optimization · Systems & Chaos
An open-town horror entry with dynamic rain that intensifies the otherworld.
Resident Evil 0 leans Optimization (Pure Optimization); Silent Hill: Downpour leans Optimization (Systems & Chaos).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Resident Evil 0
Tank-control combat is modestly demanding
Silent Hill: Downpour
Improvised melee asks little mechanical skill
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Resident Evil 0
Enemies follow fixed behaviour
Silent Hill: Downpour
Enemies and the Void are scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Resident Evil 0
Hidden layouts surprise until mapped
Silent Hill: Downpour
Weather shifts and side quests hide information first run
Resident Evil 0 leans a little harder on optimization, though the gap is small.
Resident Evil 0
Two-character item juggling makes routing the real game
Silent Hill: Downpour
Routes, puzzles, and morality endings are solvable
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.