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 · Systems & Chaos
A noir detective adventure starring Discworld's first private investigator on a case that turns lycanthropic.

Optimization · Pure Optimization
A LucasArts sci-fi adventure where astronauts stranded on an alien world puzzle out its dead civilization.
Discworld Noir leans Optimization (Systems & Chaos); The Dig 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.
Discworld Noir
Click-based sleuthing; nothing physical.
The Dig
Point-and-click; no reflex demands.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Discworld Noir
Suspects recite fixed noir scripts.
The Dig
Alien world is static; companions follow scripts.
Discworld Noir leans a little harder on variance, though the gap is small.
Discworld Noir
Clue-notebook mystery hides connections until found.
The Dig
Alien machinery's purpose is hidden until experimented with.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Discworld Noir
Cross-referencing clues converges to one fixed solution.
The Dig
Machine puzzles have single fixed solutions to deduce.
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.