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 point-and-click adventure where inventory puzzle logic is the whole challenge.

Optimization · Light / Casual
A first-person mystery about a fire lookout in a Wyoming forest.
Broken Sword: The Smoking Mirror leans Optimization (Light / Casual); Firewatch 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.
Broken Sword: The Smoking Mirror
no physical skill, point-and-click
Firewatch
Walking and radio dialogue only.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Broken Sword: The Smoking Mirror
no opponents, puzzle-driven
Firewatch
No adaptive opposition.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Broken Sword: The Smoking Mirror
no meaningful randomness
Firewatch
Minor environmental discoveries.
Broken Sword: The Smoking Mirror leans a little harder on optimization, though the gap is small.
Broken Sword: The Smoking Mirror
item puzzle logic is solvable
Firewatch
Few systems to optimize.
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.