head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
Zero awakens to lead a resistance in a harsh, rank-graded GBA action series debut.

Execution · Practiced Mastery
Memorising spawn patterns then executing them flawlessly under one-hit-death rules.
Mega Man Zero leans Execution (Practiced Mastery); Super Contra 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.
Mega Man Zero
Punishing GBA action with strict ranking on damage
Super Contra
One-hit deaths demand precise dodging and constant accurate fire
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Mega Man Zero
All bosses are pattern-based
Super Contra
Alien waves follow fixed spawn scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Mega Man Zero
Cyber-elf locations hidden at first
Super Contra
Nothing random once spawn patterns are memorised
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Mega Man Zero
Rank system penalises elf use, rewarding optimised clean runs
Super Contra
Memorising spawns and weapon routes is half the run
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.