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
The 1986 original that defined exploration-driven, secret-riddled platforming.

Optimization · Practiced Mastery
A looter-shooter loop testing build optimisation more than the shooting itself.
Metroid leans Optimization (Practiced Mastery); Suicide Squad: Kill the Justice League 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.
Metroid
stiff NES jumps and tough enemy contact
Suicide Squad: Kill the Justice League
Traversal-shooting needs moderate aim, generous by shooter standards
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid
creatures follow fixed movement
Suicide Squad: Kill the Justice League
Brainwashed bosses are scripted encounters
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid
unmarked secrets and bombable blocks hide the map
Suicide Squad: Kill the Justice League
Loot rolls gate the live-service grind
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid
route and item knowledge transforms the game
Suicide Squad: Kill the Justice League
Gear builds and mission farming dominate endgame
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.