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
A hand-drawn western take on Hotline Miami where you cock the revolver before every single shot.

Execution · Pure Mechanics
Comic-panel beat 'em up notorious for punishing health drain and tough fights.
12 is Better Than 6 leans Execution (Practiced Mastery); Comix Zone leans Execution (Pure Mechanics).
Comix Zone leans a little harder on execution, though the gap is small.
12 is Better Than 6
One-hit deaths, manual cocking, fast top-down aim
Comix Zone
Brutal one-life brawling demands clean play
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
12 is Better Than 6
Enemies are placed and scripted
Comix Zone
Enemies follow fixed attack scripts
12 is Better Than 6 leans a little harder on variance, though the gap is small.
12 is Better Than 6
Unknown enemy placements on first attempts only
Comix Zone
Everything is placed and scripted
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
12 is Better Than 6
Each room becomes a learnable clear order
Comix Zone
Panel routes and item use are memorizable
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.