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
Survival horror prequel built on swapping two characters with no item boxes.

Optimization · Pure Optimization
A 2D sandbox of procedurally generated planets driven by crafting progression.
Resident Evil 0 leans Optimization (Pure Optimization); Starbound 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.
Resident Evil 0
Tank-control combat is modestly demanding
Starbound
Light platforming and combat, generous margins
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Resident Evil 0
Enemies follow fixed behaviour
Starbound
Procedural NPCs follow simple fixed behaviours
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Resident Evil 0
Hidden layouts surprise until mapped
Starbound
Procedural planets and loot keep early exploration unknown
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Resident Evil 0
Two-character item juggling makes routing the real game
Starbound
Gear tiers, farming, and progression routes dominate
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.