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

Optimization · Pure Optimization
The expanded sequel adds desert and arctic piñatas to the garden-ecosystem puzzle.
Fallout Shelter leans Optimization (Pure Optimization); Viva Piñata: Trouble in Paradise leans Optimization (Pure Optimization).
Viva Piñata: Trouble in Paradise leans a little harder on execution, though the gap is small.
Fallout Shelter
Tapping menus only
Viva Piñata: Trouble in Paradise
Same gentle gardening controls
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
Viva Piñata: Trouble in Paradise
Creature behavior is rule-based, not adaptive
Fallout Shelter leans a little harder on variance, though the gap is small.
Fallout Shelter
Incident spawns and lunchbox loot rolls
Viva Piñata: Trouble in Paradise
New biome visitors still arrive with some chance
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
Viva Piñata: Trouble in Paradise
Expanded species web deepens the requirement-solving game
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.