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

Execution · Pure Mechanics
A minimalist top-down rally racer testing commitment, rhythm and clean car control.

Execution · Pure Mechanics
Landmark FPS built on physics puzzles and tight gunplay.
Art of Rally leans Execution (Pure Mechanics); Half-Life 2 leans Execution (Pure Mechanics).
Art of Rally leans clearly harder on execution.
Art of Rally
Minimalist top-down physics demand precise committed corner entries
Half-Life 2
Gravity gun and shooting demand precision.
Half-Life 2 leans a little harder on reads, though the gap is small.
Art of Rally
Time-attack format; no adaptive opponent
Half-Life 2
Combine AI scripted, non-adaptive.
Art of Rally leans a little harder on variance, though the gap is small.
Art of Rally
Surface grip variation and weather add mild variance
Half-Life 2
Almost no randomness.
Art of Rally leans clearly harder on optimization.
Art of Rally
Rally car and service choices form a light solvable meta-layer
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.