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

Optimization · Pure Optimization
Sprawling tactical dungeon crawler where managing a dwindling hand of cards decides everything.

Optimization · Pure Optimization
An auto-attacker where picking the right weapon evolutions wins by itself.
Gloomhaven leans Optimization (Pure Optimization); Vampire Survivors 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.
Gloomhaven
Turn-based; zero dexterity demand
Vampire Survivors
Movement is trivial; no aim or precision required.
Gloomhaven leans a little harder on reads, though the gap is small.
Gloomhaven
Monster AI follows printed, mappable rules
Vampire Survivors
Enemies follow fixed spawn scripts; no adaptive opponent.
Gloomhaven leans a little harder on variance, though the gap is small.
Gloomhaven
Modifier deck and monster ability draws
Vampire Survivors
Level-up offerings and pickup drops are randomized.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Gloomhaven
Card economy and scenario routing are the 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.