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
God game about winning worshippers through miracles and training a giant pet creature.

Optimization · Pure Optimization
A story-driven survival adventure alone on a hostile alien planet.
Black & White leans Optimization (Pure Optimization); The Solus Project leans Optimization (Pure Optimization).
The Solus Project leans a little harder on execution, though the gap is small.
Black & White
Gesture-cast miracles; minimal dexterity stakes
The Solus Project
Exploration platforming with mild precision needs
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Black & White
Rival gods follow scripted strategies
The Solus Project
No adaptive entities, only environment
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Black & White
Creature learning quirks surprise first plays
The Solus Project
Alien caves hidden until explored, single playthrough mostly
Black & White leans a little harder on optimization, though the gap is small.
Black & White
Village economy, belief spread, and creature training
The Solus Project
Managing temperature, hunger, and route planning drives survival
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.