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

Execution · Pure Mechanics
An early arcade climber demanding tight, repeatable jump execution.

Execution · Pure Mechanics
Landmark FPS built on physics puzzles and tight gunplay.
Donkey Kong Junior leans Execution (Pure Mechanics); Half-Life 2 leans Execution (Pure Mechanics).
Donkey Kong Junior leans clearly harder on execution.
Donkey Kong Junior
precise vine-climbing and jump timing
Half-Life 2
Gravity gun and shooting demand precision.
Half-Life 2 leans a little harder on reads, though the gap is small.
Donkey Kong Junior
enemies follow fixed patrol patterns
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.
Donkey Kong Junior
minor enemy timing variance
Half-Life 2
Almost no randomness.
Half-Life 2 leans a little harder on optimization, though the gap is small.
Donkey Kong Junior
minimal route memorization needed
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.