head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is optimization, and it is a single point.

Optimization · Pure Optimization
A minimalist puzzle platformer about deducing box-chain solutions.

Optimization · Pure Optimization
A puzzle game where photographs layered onto the world physically rebuild missing geometry.
BoxBoxBoy! leans Optimization (Pure Optimization); Viewfinder 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.
BoxBoxBoy!
Box creation and movement need no precision
Viewfinder
Placing photo layers needs light spatial precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
BoxBoxBoy!
Solo puzzle game with no opponent
Viewfinder
No opponent; photograph-based puzzle
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
BoxBoxBoy!
Puzzles fully deterministic, nothing random
Viewfinder
All scenes are deterministic
BoxBoxBoy! leans a little harder on optimization, though the gap is small.
BoxBoxBoy!
Deducing box-chain shapes to clear obstacles is the game
Viewfinder
Deducing which photo angle reconstructs the geometry needed to progress
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.