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
Following authored stealth-fear sequences with learnable intended solutions.

Optimization · Practiced Mastery
Haunted-hotel adventure climbing themed floors with vacuum and goo clone.
Batman Begins leans Optimization (Practiced Mastery); Luigi's Mansion 3 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.
Batman Begins
Combat and stealth inputs are forgiving
Luigi's Mansion 3
Slam combos and boss-dodge timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Batman Begins
Guards follow scripted fear and patrol patterns
Luigi's Mansion 3
Floor bosses run fixed scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Batman Begins
Encounters are staged identically every run
Luigi's Mansion 3
Hotel floors are authored
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Batman Begins
Each fear-scripted sequence has an intended solution to find
Luigi's Mansion 3
Gooigi puzzles and gem routes are 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.