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

Optimization · Pure Optimization
Lane defense classic about managing a sun economy against shambling waves.

Optimization · Pure Optimization
Exploiting the press-turn system through demon fusion and weakness math.
Plants vs. Zombies leans Optimization (Pure Optimization); Shin Megami Tensei: Nocturne leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Plants vs. Zombies
Clicking to plant, minimal pressure
Shin Megami Tensei: Nocturne
Turn-based menus carry zero dexterity demands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Plants vs. Zombies
Zombie waves follow set compositions
Shin Megami Tensei: Nocturne
Brutal bosses still run fixed scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Plants vs. Zombies
Wave timing and lane pressure vary mildly
Shin Megami Tensei: Nocturne
Unknown boss gimmicks and fusion luck sting first attempts
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Plants vs. Zombies
Sun economy and lane setups are near-solvable
Shin Megami Tensei: Nocturne
Press-turn exploitation and fusion planning decide everything
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.