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
Routing scripted patrols with vampire teleports and a light skill-build layer.

Optimization · Practiced Mastery
A puzzle-leaning platformer testing perspective-flip problem solving more than reflexes.
Dark leans Optimization (Practiced Mastery); Super Paper Mario 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.
Dark
Shadow-teleport timing matters but combat is clunky-forgiving
Super Paper Mario
Light platforming demands, well below mainline Mario
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Dark
Guards run scripted patrol and alert routines
Super Paper Mario
Enemies follow simple fixed patterns, no adaptation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dark
Patrols are fixed once observed
Super Paper Mario
Dimension-flip secrets are scripted-but-unknown until found
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Dark
Skill builds and patrol routing solve each stealth arena
Super Paper Mario
Solving levels via the 2D/3D flip mechanic is the core test
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.