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

Optimization · Practiced Mastery
Co-op first-person zombie RPG about improvised weapons on a resort island.

Optimization · Practiced Mastery
An action horror game where a death-row inmate fights execution-themed monsters during a prison island breakout.
Dead Island leans Optimization (Practiced Mastery); The Suffering leans Optimization (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
first-person melee timing and stamina
The Suffering
Fast shooting and the Insanity transformation reward sharp play
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Dead Island
zombies are scripted swarms
The Suffering
Malefactors attack on fixed archetype patterns
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dead Island
weapon drops and spawns add noise
The Suffering
Unknown spawns and morality outcomes on a blind run
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Dead Island
weapon mods and skill builds carry late game
The Suffering
Weapon choice, rage meter use, and routes are learnable
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.