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

Optimization · Light / Casual
A meditative picture-book stroll with pressure-free terrain puzzles.
Firewatch leans Optimization (Light / Casual); Old Man's Journey leans Optimization (Light / Casual).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Firewatch
Walking and radio dialogue only.
Old Man's Journey
Dragging hills around requires no dexterity
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.
Old Man's Journey
No opponent exists
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Firewatch
Minor environmental discoveries.
Old Man's Journey
Nothing meaningfully hidden or random
Old Man's Journey leans a little harder on optimization, though the gap is small.
Firewatch
Few systems to optimize.
Old Man's Journey
Gentle terrain puzzles with obvious solutions
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.