head to head
Zenzizenzic 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 twin-stick bullet-hell shooter testing reflexes against dense projectile patterns.
Half-Life 2 leans Execution (Pure Mechanics); Zenzizenzic leans Execution (Pure Mechanics).
Zenzizenzic leans clearly harder on execution.
Half-Life 2
Gravity gun and shooting demand precision.
Zenzizenzic
Dodging dense bullet patterns at speed is the lead axis
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Half-Life 2
Combine AI scripted, non-adaptive.
Zenzizenzic
Enemies fire scripted patterns, no adaptive mind
Zenzizenzic leans clearly harder on variance.
Half-Life 2
Almost no randomness.
Zenzizenzic
Spawn variety and power-up drops add minor randomness
Zenzizenzic leans clearly harder on optimization.
Half-Life 2
Linear progression with no builds.
Zenzizenzic
Weapon and power-up choices optimize survival potential
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.