head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Optimization · Pure Optimization
Dungeon-crawling PS1 sequel built around DNA digivolution and grinding through randomized domains.

Optimization · Pure Optimization
An auto-attacker where picking the right weapon evolutions wins by itself.
Digimon World 2 leans Optimization (Pure Optimization); Vampire Survivors leans Optimization (Pure Optimization).
Vampire Survivors leans a little harder on execution, though the gap is small.
Digimon World 2
Turn-based dungeon crawling; no dexterity
Vampire Survivors
Movement is trivial; no aim or precision required.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Digimon World 2
Fixed AI encounters only
Vampire Survivors
Enemies follow fixed spawn scripts; no adaptive opponent.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Digimon World 2
Random dungeon layouts and recruitment rolls
Vampire Survivors
Level-up offerings and pickup drops are randomized.
Vampire Survivors leans a little harder on optimization, though the gap is small.
Digimon World 2
DNA digivolving and party math are the whole game
Vampire Survivors
Evolution paths and weapon combinations fully solve the run.
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.