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 visual novel thriller mixing escape-room puzzles with branching life-or-death story routes.

Optimization · Systems & Chaos
An audio detective game where you identify suspects by eavesdropping on crime-scene recordings.
999: Nine Hours, Nine Persons, Nine Doors leans Optimization (Systems & Chaos); Unheard leans Optimization (Systems & Chaos).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
999: Nine Hours, Nine Persons, Nine Doors
Tapping through text and puzzles, zero dexterity
Unheard
Just scrubbing a timeline and listening
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
999: Nine Hours, Nine Persons, Nine Doors
Characters follow a fixed script, never adapt
Unheard
No opponent, recorded voices only
Unheard leans a little harder on variance, though the gap is small.
999: Nine Hours, Nine Persons, Nine Doors
Hidden story branches and twists drive first playthroughs
Unheard
Identities are hidden until audio clues connect
Unheard leans a little harder on optimization, though the gap is small.
999: Nine Hours, Nine Persons, Nine Doors
Escape-room puzzles and route flowchart are fully solvable
Unheard
Cross-referencing fixed conversations solves each case
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.