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 surreal escape room testing deduction of hidden item-and-puzzle chains.

Optimization · Pure Optimization
A vault management sim about optimising dwellers, rooms, and resource loops.
Cube Escape: Birthday leans Optimization (Pure Optimization); Fallout Shelter 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.
Cube Escape: Birthday
Pointing and clicking, zero dexterity
Fallout Shelter
Tapping menus only
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Cube Escape: Birthday
Fully scripted scenes, nothing adapts
Fallout Shelter
No opponent
Fallout Shelter leans a little harder on variance, though the gap is small.
Cube Escape: Birthday
Puzzle logic is hidden until items are discovered
Fallout Shelter
Incident spawns and lunchbox loot rolls
Fallout Shelter leans a little harder on optimization, though the gap is small.
Cube Escape: Birthday
Each surreal puzzle has one fixed solvable answer
Fallout Shelter
Dweller stats and room layout are fully 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.