head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is optimization, and it is a single point.

Execution · Pure Mechanics
Peak 16-bit run-and-gun of set-piece bosses and razor-thin dodges.

Execution · Pure Mechanics
Twitch dodging and aim under fire, with score routes rewarding memorisation.
Contra III: The Alien Wars leans Execution (Pure Mechanics); Sin & Punishment: Star Successor leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Contra III: The Alien Wars
Relentless bosses and bullet dodging
Sin & Punishment: Star Successor
Dodging dense bullet patterns while aiming is a motor ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Contra III: The Alien Wars
Set-piece bosses are pure scripts
Sin & Punishment: Star Successor
Bosses follow elaborate but fixed scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Contra III: The Alien Wars
Everything is fixed and learnable
Sin & Punishment: Star Successor
Everything is deterministic once patterns are seen
Contra III: The Alien Wars leans a little harder on optimization, though the gap is small.
Contra III: The Alien Wars
Weapon management and pattern memorization
Sin & Punishment: Star Successor
Multiplier preservation routes drive leaderboard play
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.