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

Optimization · Systems & Chaos
Calm exploration and environmental puzzle-solving under light oxygen pressure.

Optimization · Systems & Chaos
Puzzle adventure about coaxing a giant half-tame creature through ancient ruins.
Deliver Us the Moon leans Optimization (Systems & Chaos); The Last Guardian leans Optimization (Systems & Chaos).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Deliver Us the Moon
Oxygen-timed traversal asks for calm, not twitch
The Last Guardian
Slow climbing and platforming, very forgiving
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Deliver Us the Moon
No opponent exists on the abandoned moon
The Last Guardian
Trico is willful but not modeling you adversarially
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Deliver Us the Moon
Station layouts and story logs are unknown until explored
The Last Guardian
Trico's unpredictable compliance adds noise
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Deliver Us the Moon
Environmental puzzles have single discoverable solutions
The Last Guardian
Environmental puzzles with intended solutions
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.