head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Light / Casual
Branching interactive thriller where QTE choices decide who survives the Origami Killer case.

Execution · Light / Casual
A first-person horror about a journalist investigating an asylum.
Heavy Rain leans Execution (Light / Casual); Outlast 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.
Heavy Rain
QTE prompts under tension
Outlast
Running, hiding, and camera use.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Heavy Rain
No adaptive opposition
Outlast
Enemies follow scripts.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Heavy Rain
First-run uncertainty about consequences
Outlast
Mild patrol variance.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Heavy Rain
Branch knowledge fully solves outcomes
Outlast
Battery and route planning shallow.
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.