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

Execution · Practiced Mastery
A Space Invaders descendant testing arcade aim plus an upgrade-economy layer.
Comix Zone leans Execution (Pure Mechanics); Titan Attacks! leans Execution (Practiced Mastery).
Comix Zone leans a little harder on execution, though the gap is small.
Comix Zone
Brutal one-life brawling demands clean play
Titan Attacks!
Dodging fire while sniping descending waves is pure arcade aim
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
Titan Attacks!
Alien waves follow fixed formations
Titan Attacks! leans a little harder on variance, though the gap is small.
Comix Zone
Everything is placed and scripted
Titan Attacks!
Bounty drops and saucer timing add minor noise
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Comix Zone
Panel routes and item use are memorizable
Titan Attacks!
Upgrade purchases between waves form a small economy to solve
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.