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
Colour-painting terrain puzzles that resolve to finding the intended solution.

Optimization · Pure Optimization
A physics puzzle-platformer about swapping three heroes to improvise solutions.
Nihilumbra leans Optimization (Pure Optimization); Trine 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.
Nihilumbra
Some platforming timing, but forgiving throughout
Trine
Physics platforming and wizard-box stacking need dexterity
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Nihilumbra
Enemies cannot be fought or read, only avoided
Trine
No opponent; puzzles are fixed
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Nihilumbra
Hand-designed puzzles with nothing random
Trine
Levels are static and fully visible
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Nihilumbra
Choosing which colour solves each terrain puzzle is the game
Trine
Choosing the right hero and contraption solves each obstacle
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.