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
Demanding platform execution plus a solvable boss-weakness ordering puzzle.

Execution · Practiced Mastery
Memorising spawn patterns then executing them flawlessly under one-hit-death rules.
Mega Man 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
Pixel-precise jumps and shots against brutal fixed stages
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
Robot Masters cycle rigid scripted patterns
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
Nothing changes between attempts
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
Boss-order weakness routing is a known solvable layer
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.