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 wordless atmospheric pilgrimage across dunes toward a distant mountain.

Optimization · Light / Casual
Atompunk walking sim adapting Lem's novel about a hostile robotic planet.
Journey leans Optimization (Light / Casual); The Invincible 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.
Journey
Gentle gliding with no fail pressure
The Invincible
Walking and dialogue choices only
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Journey
Anonymous companions cooperate, never oppose
The Invincible
No opposition of any kind
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Journey
World is fixed and linear
The Invincible
Authored story with branching endings
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Journey
Light scarf-collecting routes at most
The Invincible
Light exploration; choices steer narrative
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.