head to head
Tony Hawk's Pro Skater 5 asks more than Half-Life 2, and the gap is execution.

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

Execution · Pure Mechanics
A skateboarding game about chaining trick combos across stylized levels.
Half-Life 2 leans Execution (Pure Mechanics); Tony Hawk's Pro Skater 5 leans Execution (Pure Mechanics).
Tony Hawk's Pro Skater 5 leans clearly harder on execution.
Half-Life 2
Gravity gun and shooting demand precision.
Tony Hawk's Pro Skater 5
trick-combo timing and balance execution
Half-Life 2 leans a little harder on reads, though the gap is small.
Half-Life 2
Combine AI scripted, non-adaptive.
Tony Hawk's Pro Skater 5
no adversarial adapting opponent
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Half-Life 2
Almost no randomness.
Tony Hawk's Pro Skater 5
minimal randomness
Tony Hawk's Pro Skater 5 leans a little harder on optimization, though the gap is small.
Half-Life 2
Linear progression with no builds.
Tony Hawk's Pro Skater 5
combo-route and score-tech optimization
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.