head to head
Butcher asks more than Half-Life 2, and the gap is execution.

Execution · Pure Mechanics
Punishing 2D gunplay that tests raw aim and movement against fixed deadly rooms.

Execution · Pure Mechanics
Landmark FPS built on physics puzzles and tight gunplay.
Butcher leans Execution (Pure Mechanics); Half-Life 2 leans Execution (Pure Mechanics).
Butcher leans clearly harder on execution.
Butcher
Brutal twitch aim and movement under instant-death pressure
Half-Life 2
Gravity gun and shooting demand precision.
Half-Life 2 leans a little harder on reads, though the gap is small.
Butcher
Enemy placements and behaviours are fixed scripts
Half-Life 2
Combine AI scripted, non-adaptive.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Butcher
Levels are deterministic, runs differ only by your play
Half-Life 2
Almost no randomness.
Butcher leans a little harder on optimization, though the gap is small.
Butcher
Weapon choice and room routing reward study
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.