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

Execution · Practiced Mastery
Landmark scripted FPS following Gordon Freeman through the Black Mesa disaster.

Execution · Practiced Mastery
A vertical shmup where careful upgrade investment and bullet-threading execution drive progression through increasingly dense stages.
Half-Life leans Execution (Practiced Mastery); Sky Force Reloaded leans Execution (Practiced Mastery).
Sky Force Reloaded leans a little harder on execution, though the gap is small.
Half-Life
Combat aim and infamous platforming sections
Sky Force Reloaded
Precise movement through bullet curtains and timing shields is decisive
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Half-Life
Marines flank by script, not by modelling you
Sky Force Reloaded
All enemies are scripted; no adaptive opponent
Sky Force Reloaded leans a little harder on variance, though the gap is small.
Half-Life
Set pieces surprise only on first run
Sky Force Reloaded
Power-up drops and enemy sub-patterns introduce per-run variation
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Half-Life
Resource routing and encounter knowledge for speedruns
Sky Force Reloaded
Upgrade investment, medal grinding paths, and star usage are optimisable
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.