head to head
Neither is simply harder - they are hard in different places. Danganronpa V3: Killing Harmony demands more variance; Portal demands more execution.

Optimization · Pure Optimization
The most mechanically varied Danganronpa trial system, wrapping a meta-narrative puzzle about fiction and truth.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Danganronpa V3: Killing Harmony leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Danganronpa V3: Killing Harmony
New Debate Scrum and other trial modes add mild timing
Portal
Portal placement timing modest.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Danganronpa V3: Killing Harmony
Culprits are predetermined; no adaptive deduction layer
Portal
No adversary modeling player.
Danganronpa V3: Killing Harmony leans clearly harder on variance.
Danganronpa V3: Killing Harmony
Truth Bullets and hidden evidence shape trial uncertainty
Portal
Deterministic chambers; no randomness.
Portal leans a little harder on optimization, though the gap is small.
Danganronpa V3: Killing Harmony
Mastering all trial minigames and argument logic is the optimisable path
Portal
Pure puzzle-solving optimization.
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.