head to head
The Blue Flamingo 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 top-down shoot-em-up testing reflexes with a score-gambling upgrade twist.
Half-Life 2 leans Execution (Pure Mechanics); The Blue Flamingo leans Execution (Pure Mechanics).
The Blue Flamingo leans clearly harder on execution.
Half-Life 2
Gravity gun and shooting demand precision.
The Blue Flamingo
Dodging bullets and aiming is the whole loop
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.
The Blue Flamingo
Enemy waves are scripted, not adaptive
The Blue Flamingo leans clearly harder on variance.
Half-Life 2
Almost no randomness.
The Blue Flamingo
Enemy patterns mostly fixed with minor randomness
The Blue Flamingo leans a little harder on optimization, though the gap is small.
Half-Life 2
Linear progression with no builds.
The Blue Flamingo
Score-banking upgrade gambling adds light strategy
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.