head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is optimization, and it is a single point.

Optimization · Pure Optimization
A hidden-object mystery about searching scenes and solving puzzles to crack a case.

Optimization · Pure Optimization
A school murder mystery where class trials test players' ability to assemble evidence into the correct counter-argument.
9 Clues: The Secret of Serpent Creek leans Optimization (Pure Optimization); Danganronpa: Trigger Happy Havoc 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.
9 Clues: The Secret of Serpent Creek
Clicking hidden objects needs only patience
Danganronpa: Trigger Happy Havoc
Class trial rhythm sections add minor timing layer
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
9 Clues: The Secret of Serpent Creek
No adaptive opponent in a casual mystery
Danganronpa: Trigger Happy Havoc
Blackened is scripted per chapter; no adaptive deduction opponent
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
9 Clues: The Secret of Serpent Creek
Object and clue locations hidden until found
Danganronpa: Trigger Happy Havoc
Hidden killer identities and evidence drive trial uncertainty
Danganronpa: Trigger Happy Havoc leans a little harder on optimization, though the gap is small.
9 Clues: The Secret of Serpent Creek
Working through puzzles and deductions is the loop
Danganronpa: Trigger Happy Havoc
Gathering evidence and building the correct argument chain is a solvable deduction loop
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.
full breakdown
9 Clues: The Secret of Serpent Creek →
full breakdown
Danganronpa: Trigger Happy Havoc →