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

Optimization · Light / Casual
A first-person mystery about a fire lookout in a Wyoming forest.

Optimization · Light / Casual
Tests nothing competitive - an authored interactive memoir to experience.
Firewatch leans Optimization (Light / Casual); If Found... leans Optimization (Light / Casual).
Firewatch leans a little harder on execution, though the gap is small.
Firewatch
Walking and radio dialogue only.
If Found...
Erasing pages takes no skill by design
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Firewatch
No adaptive opposition.
If Found...
No opponent in a linear memoir
Firewatch leans a little harder on variance, though the gap is small.
Firewatch
Minor environmental discoveries.
If Found...
Fully authored with nothing random
Firewatch leans a little harder on optimization, though the gap is small.
Firewatch
Few systems to optimize.
If Found...
Nothing to solve - the story simply unfolds
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.