head to head
Boxing asks more than Half-Life 2, and the gap is reads.

Execution · Pure Mechanics
A two-minute test of joystick reflexes and simple punch-trading rhythm.

Execution · Pure Mechanics
Landmark FPS built on physics puzzles and tight gunplay.
Boxing leans Execution (Pure Mechanics); Half-Life 2 leans Execution (Pure Mechanics).
Boxing leans a little harder on execution, though the gap is small.
Boxing
Joystick speed and punch timing decide the two-minute bout
Half-Life 2
Gravity gun and shooting demand precision.
Boxing leans clearly harder on reads.
Boxing
A human second player can be baited and predicted
Half-Life 2
Combine AI scripted, non-adaptive.
Half-Life 2 leans a little harder on variance, though the gap is small.
Boxing
Nothing hidden or random in the ring
Half-Life 2
Almost no randomness.
Half-Life 2 leans a little harder on optimization, though the gap is small.
Boxing
Scoring rules are shallow; positioning tricks are quickly learned
Half-Life 2
Linear progression with no builds.
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.