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
An open-world RPG whose min-maxable leveling and build system dominate over its clunky combat.

Optimization · Pure Optimization
A scripted RPG where pattern-learning and pacifist routing carry you.
The Elder Scrolls IV: Oblivion Remastered leans Optimization (Pure Optimization); Undertale leans Optimization (Pure Optimization).
Undertale leans a little harder on execution, though the gap is small.
The Elder Scrolls IV: Oblivion Remastered
real-time combat but forgiving swings
Undertale
Bullet-hell dodging in scripted patterns
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
The Elder Scrolls IV: Oblivion Remastered
NPCs follow scripted AI packages
Undertale
NPCs follow fixed dialogue trees, not adaptive
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
The Elder Scrolls IV: Oblivion Remastered
loot/leveling has some randomness
Undertale
Minimal randomness in encounters
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
The Elder Scrolls IV: Oblivion Remastered
leveling system, builds min-maxable
Undertale
Learning fixed boss patterns and mercy routes wins
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.