head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Optimization · Pure Optimization
A vault management sim about optimising dwellers, rooms, and resource loops.

Optimization · Pure Optimization
A kingdom-management narrative where you ration gold and favors as a beleaguered king.
Fallout Shelter leans Optimization (Pure Optimization); Yes, Your Grace 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.
Fallout Shelter
Tapping menus only
Yes, Your Grace
Menu choices only
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout Shelter
No opponent
Yes, Your Grace
Petitioners are scripted, not adaptive
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout Shelter
Incident spawns and lunchbox loot rolls
Yes, Your Grace
Outcomes of choices hidden on first run
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout Shelter
Dweller stats and room layout are fully solvable
Yes, Your Grace
Resource budgeting across known story beats is 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.