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
Nintendo's daily mental-workout collection of arithmetic, reading, and memory drills.

Optimization · Practiced Mastery
A story-retelling action RPG that relives the Z saga.
Brain Age: Train Your Brain in Minutes a Day! leans Optimization (Practiced Mastery); Dragon Ball Z: Kakarot 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.
Brain Age: Train Your Brain in Minutes a Day!
Fast writing and speech input under time pressure
Dragon Ball Z: Kakarot
Forgiving arena combat with light timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Brain Age: Train Your Brain in Minutes a Day!
No opponent
Dragon Ball Z: Kakarot
Bosses replay fixed movesets
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Brain Age: Train Your Brain in Minutes a Day!
Problem sets are randomly drawn but simple
Dragon Ball Z: Kakarot
Story content, little randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Brain Age: Train Your Brain in Minutes a Day!
Mental arithmetic shortcuts and practice drive scores
Dragon Ball Z: Kakarot
Levels, communities, and cooking trivialise fights
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.