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

Optimization · Pure Optimization
A 2D sandbox where preparation and gear tiering carry boss fights.

Optimization · Pure Optimization
An open-world mech JRPG whose combat rewards deep system and build optimization.
Terraria leans Optimization (Pure Optimization); Xenoblade Chronicles X 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.
Terraria
Boss fights require dodging and aim under pressure.
Xenoblade Chronicles X
positioning and arts timing in combat
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Terraria
Bosses use scripted attacks; no adaptation.
Xenoblade Chronicles X
solo JRPG, no adapting opponent
Terraria leans a little harder on variance, though the gap is small.
Terraria
World seeds and loot drops randomized.
Xenoblade Chronicles X
drop rates and crit rolls
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Terraria
Gear progression and arena prep solve every boss.
Xenoblade Chronicles X
deep build/skill/gear system to optimize
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.