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

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

Optimization · Light / Casual
A surreal psychological horror visual novel steeped in unsettling imagery.
Firewatch leans Optimization (Light / Casual); Hello Charlotte Ep.1: Junk Food, Gods and Teddy Bears 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.
Hello Charlotte Ep.1: Junk Food, Gods and Teddy Bears
minimal interaction, narrative-focused
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.
Hello Charlotte Ep.1: Junk Food, Gods and Teddy Bears
no adversarial opponent present
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.
Hello Charlotte Ep.1: Junk Food, Gods and Teddy Bears
negligible randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Firewatch
Few systems to optimize.
Hello Charlotte Ep.1: Junk Food, Gods and Teddy Bears
linear story exploration, little to solve
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.