head to head
Colin McRae Rally 04 asks more than Half-Life 2, and the gap is execution.

Execution · Pure Mechanics
Committed rally driving where memorised stages meet precise throttle-and-slide control.

Execution · Pure Mechanics
Landmark FPS built on physics puzzles and tight gunplay.
Colin McRae Rally 04 leans Execution (Pure Mechanics); Half-Life 2 leans Execution (Pure Mechanics).
Colin McRae Rally 04 leans clearly harder on execution.
Colin McRae Rally 04
Millisecond car control on loose surfaces is the whole test
Half-Life 2
Gravity gun and shooting demand precision.
Half-Life 2 leans a little harder on reads, though the gap is small.
Colin McRae Rally 04
Solo against the stage clock
Half-Life 2
Combine AI scripted, non-adaptive.
Colin McRae Rally 04 leans a little harder on variance, though the gap is small.
Colin McRae Rally 04
Damage and surface conditions add minor unknowns
Half-Life 2
Almost no randomness.
Colin McRae Rally 04 leans clearly harder on optimization.
Colin McRae Rally 04
Setup tuning and stage memorisation compound lap time
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.