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.

Variance · Light / Casual
A horror sound-novel chapter testing attention to an unfolding rural mystery.
Firewatch leans Optimization (Light / Casual); Higurashi When They Cry Hou: Ch.3 Tatarigoroshi leans Variance (Light / Casual).
Firewatch leans a little harder on execution, though the gap is small.
Firewatch
Walking and radio dialogue only.
Higurashi When They Cry Hou: Ch.3 Tatarigoroshi
Reading text; no physical demand
Higurashi When They Cry Hou: Ch.3 Tatarigoroshi leans a little harder on reads, though the gap is small.
Firewatch
No adaptive opposition.
Higurashi When They Cry Hou: Ch.3 Tatarigoroshi
Authored mystery with no adaptive opponent
Higurashi When They Cry Hou: Ch.3 Tatarigoroshi leans a little harder on variance, though the gap is small.
Firewatch
Minor environmental discoveries.
Higurashi When They Cry Hou: Ch.3 Tatarigoroshi
Hidden mystery details unfold but story is fixed
Firewatch leans a little harder on optimization, though the gap is small.
Firewatch
Few systems to optimize.
Higurashi When They Cry Hou: Ch.3 Tatarigoroshi
Little to solve mechanically; it is reading
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.