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

Execution · Pure Mechanics
Landmark FPS built on physics puzzles and tight gunplay.

Execution · Pure Mechanics
A grim top-down shooter testing aim and crowd dodging through fixed levels.
Half-Life 2 leans Execution (Pure Mechanics); Postal: Redux leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Half-Life 2
Gravity gun and shooting demand precision.
Postal: Redux
Isometric aim and dodging hostile crowds is the test
Half-Life 2 leans a little harder on reads, though the gap is small.
Half-Life 2
Combine AI scripted, non-adaptive.
Postal: Redux
Hostiles charge by simple fixed logic
Postal: Redux leans a little harder on variance, though the gap is small.
Half-Life 2
Almost no randomness.
Postal: Redux
Spawn placement varies runs slightly
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Half-Life 2
Linear progression with no builds.
Postal: Redux
Weapon economy and level knowledge help modestly
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.