head to head
Contra 4 asks more than Super Mario World, and the gap is execution.

Execution · Pure Mechanics
Flawless execution of memorised patterns under one-hit-death pressure.

Execution · Pure Mechanics
Precise jump execution across fixed levels with secrets to memorise.
Contra 4 leans Execution (Pure Mechanics); Super Mario World leans Execution (Pure Mechanics).
Contra 4 leans clearly harder on execution.
Contra 4
One-hit deaths under dense bullet patterns demand near-perfect inputs
Super Mario World
Perfect inputs trivialise every jump, spin and cape flight
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Contra 4
Every enemy and boss is a fixed script
Super Mario World
Scripted Koopas adapt to nothing
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Contra 4
Spawns and patterns are identical every run
Super Mario World
Levels are fixed; nothing hidden survives one playthrough
Contra 4 leans a little harder on optimization, though the gap is small.
Contra 4
Memorising layouts and weapon routing enables the execution
Super Mario World
Secret exits and route knowledge add a modest solvable layer
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.