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

Execution · Practiced Mastery
First-person melee timing against scripted hordes, supported by a craftable weapon economy.

Execution · Practiced Mastery
An action RPG where narrative depth is paired with moderately solvable combat systems.
Dead Island 2 leans Execution (Practiced Mastery); NieR leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Dead Island 2
Melee timing, dodges and zombie crowd control need decent hands
NieR
combat timing and dodges matter
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Dead Island 2
Zombies follow scripted aggression patterns, never model you
NieR
scripted enemies, no adaptation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dead Island 2
Loot drops and zombie spawns add mild run-to-run noise
NieR
loot and encounter randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Dead Island 2
Weapon mods, skill cards and elemental matchups reward planning
NieR
builds and side systems solvable
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.