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
Procedural space exploration sandbox with crafting depth.

Optimization · Pure Optimization
Item-shop management sim where you set prices to pay off a fairy's loan.
No Man's Sky leans Optimization (Pure Optimization); Recettear: An Item Shop's Tale 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.
No Man's Sky
Light shooter and flight inputs
Recettear: An Item Shop's Tale
Light action combat in optional dungeon crawls.
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
Recettear: An Item Shop's Tale
Customer haggling follows mappable scripted tolerances.
Recettear: An Item Shop's Tale leans a little harder on variance, though the gap is small.
No Man's Sky
Procedural planets and loot
Recettear: An Item Shop's Tale
Market price swings and dungeon loot rolls.
Recettear: An Item Shop's Tale leans a little harder on optimization, though the gap is small.
No Man's Sky
Base, freighter, expedition progression
Recettear: An Item Shop's Tale
Pricing margins, stock, and debt schedule are nearly 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.