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

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

Optimization · Light / Casual
Hand-illustrated psychological horror about recurring nightmares, light on mechanics.
Firewatch leans Optimization (Light / Casual); Neverending Nightmares 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.
Neverending Nightmares
Slow walking with rare evasion moments
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.
Neverending Nightmares
Threats follow simple scripts
Neverending Nightmares leans a little harder on variance, though the gap is small.
Firewatch
Minor environmental discoveries.
Neverending Nightmares
Unknown branching until explored
Neverending Nightmares leans a little harder on optimization, though the gap is small.
Firewatch
Few systems to optimize.
Neverending Nightmares
Learning enemy routes through repeating nightmares
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.