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
Procedural space exploration sandbox with crafting depth.

Optimization · Pure Optimization
A 2D sandbox where preparation and gear tiering carry boss fights.
No Man's Sky leans Optimization (Pure Optimization); Terraria leans Optimization (Pure Optimization).
Terraria leans a little harder on execution, though the gap is small.
No Man's Sky
Light shooter and flight inputs
Terraria
Boss fights require dodging and aim under pressure.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
No Man's Sky
Mostly solo, sparse PvP
Terraria
Bosses use scripted attacks; no adaptation.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
No Man's Sky
Procedural planets and loot
Terraria
World seeds and loot drops randomized.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
No Man's Sky
Base, freighter, expedition progression
Terraria
Gear progression and arena prep solve every boss.
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.