head to head
Manhunt 2 asks more than Portal, and the gap is variance.

Optimization · Pure Optimization
A transgressive stealth horror game about an asylum escapee executing hunters from the shadows.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Manhunt 2 leans Optimization (Pure Optimization); Portal 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.
Manhunt 2
Execution-hold timing and stealth movement need steady hands
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.
Manhunt 2
Hunter AI patrols on fixed search scripts
Portal
No adversary modeling player.
Manhunt 2 leans clearly harder on variance.
Manhunt 2
Unknown patrol layouts until a level is scouted
Portal
Deterministic chambers; no randomness.
Portal leans a little harder on optimization, though the gap is small.
Manhunt 2
Shadow routes and lure setups make levels solvable puzzles
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.