head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is reads, and it is a single point.

Execution · Pure Mechanics
Quarter-munching brawler reflexes against fully scripted enemy waves.

Execution · Pure Mechanics
Landmark FPS built on physics puzzles and tight gunplay.
Captain America and the Avengers leans Execution (Pure Mechanics); Half-Life 2 leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Captain America and the Avengers
Crowd management and boss dodging need arcade reflexes
Half-Life 2
Gravity gun and shooting demand precision.
Half-Life 2 leans a little harder on reads, though the gap is small.
Captain America and the Avengers
Enemies attack in fixed scripted waves
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.
Captain America and the Avengers
Nothing meaningful is random
Half-Life 2
Almost no randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Captain America and the Avengers
Memorising spawns and boss patterns stretches each credit
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.