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

Optimization · Practiced Mastery
The original tomb-crawling platformer, a spatial puzzle solved with careful jumps.
Nihilumbra leans Optimization (Pure Optimization); Tomb Raider leans Optimization (Practiced Mastery).
Tomb Raider leans a little harder on execution, though the gap is small.
Nihilumbra
Some platforming timing, but forgiving throughout
Tomb Raider
Grid-based jumps need deliberate, precise positioning
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
Tomb Raider
Wildlife and guardians follow fixed scripts
Tomb Raider leans a little harder on variance, though the gap is small.
Nihilumbra
Hand-designed puzzles with nothing random
Tomb Raider
First-run trap and secret locations are unknown
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
Tomb Raider
Levels are spatial puzzles with solvable routes
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.