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
Two Spider-Men, faster traversal, and deeper combo systems.

Execution · Practiced Mastery
A classic arcade brawler sending the turtles through time to pummel Foot Clan waves.
Marvel's Spider-Man 2 leans Execution (Practiced Mastery); Teenage Mutant Ninja Turtles IV: Turtles in Time leans Execution (Practiced Mastery).
Teenage Mutant Ninja Turtles IV: Turtles in Time leans a little harder on execution, though the gap is small.
Marvel's Spider-Man 2
Symbiote and dual-hero combat demands inputs.
Teenage Mutant Ninja Turtles IV: Turtles in Time
Throw timing, positioning, and boss dodges are the whole test.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Marvel's Spider-Man 2
Enemies scripted, not modeling player.
Teenage Mutant Ninja Turtles IV: Turtles in Time
Foot Soldiers run fixed scripts.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Marvel's Spider-Man 2
Light open-world randomness.
Teenage Mutant Ninja Turtles IV: Turtles in Time
Stages and waves are essentially fixed.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Marvel's Spider-Man 2
Expanded skill trees and gadget combos solvable.
Teenage Mutant Ninja Turtles IV: Turtles in Time
Wave layouts and boss patterns are fully memorisable.
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.
full breakdown
Marvel's Spider-Man 2 →
full breakdown
Teenage Mutant Ninja Turtles IV: Turtles in Time →