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

Execution · Pure Mechanics
Comic-panel beat 'em up notorious for punishing health drain and tough fights.

Execution · Practiced Mastery
Twitch dodging and shooting over fully memorisable enemy wave patterns.
Comix Zone leans Execution (Pure Mechanics); Star Soldier leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Comix Zone
Brutal one-life brawling demands clean play
Star Soldier
Dodging dense fire and rapid shooting carry every run
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Comix Zone
Enemies follow fixed attack scripts
Star Soldier
Enemy waves are identical scripted formations
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Comix Zone
Everything is placed and scripted
Star Soldier
Nothing random once spawn patterns are learned
Star Soldier leans a little harder on optimization, though the gap is small.
Comix Zone
Panel routes and item use are memorizable
Star Soldier
Memorising waves and power-up routes defines high scores
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.