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.

Execution · Light / Casual
A first-person horror about a journalist investigating an asylum.

Execution · Light / Casual
A visual novel with light rhythm-based minigame segments.
Outlast leans Execution (Light / Casual); Symphonic Rain leans Execution (Light / Casual).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Outlast
Running, hiding, and camera use.
Symphonic Rain
light rhythm-timing input needed
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Outlast
Enemies follow scripts.
Symphonic Rain
no opponent to out-predict
Outlast leans a little harder on variance, though the gap is small.
Outlast
Mild patrol variance.
Symphonic Rain
minor branching randomness
Outlast leans a little harder on optimization, though the gap is small.
Outlast
Battery and route planning shallow.
Symphonic Rain
minimal systems beyond song mastery
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.