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
A 2D sandbox of procedurally generated planets driven by crafting progression.

Optimization · Pure Optimization
Classic open-world RPG where stats and broken crafting systems trump twitch skill.
Starbound leans Optimization (Pure Optimization); The Elder Scrolls III: Morrowind leans Optimization (Pure Optimization).
Starbound leans a little harder on execution, though the gap is small.
Starbound
Light platforming and combat, generous margins
The Elder Scrolls III: Morrowind
Dice-roll combat ignores aim skill
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Starbound
Procedural NPCs follow simple fixed behaviours
The Elder Scrolls III: Morrowind
No adaptive opposition
Starbound leans a little harder on variance, though the gap is small.
Starbound
Procedural planets and loot keep early exploration unknown
The Elder Scrolls III: Morrowind
Hit chances rolled behind the screen
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Starbound
Gear tiers, farming, and progression routes dominate
The Elder Scrolls III: Morrowind
Alchemy and spellcrafting are famously solvable
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.