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 · Pure Mechanics
A cover-based run-and-gun testing precise shooting and pattern memorization.

Execution · Practiced Mastery
A classic arcade brawler sending the turtles through time to pummel Foot Clan waves.
Rolling Thunder 2 leans Execution (Pure Mechanics); Teenage Mutant Ninja Turtles IV: Turtles in Time leans Execution (Practiced Mastery).
Rolling Thunder 2 leans a little harder on execution, though the gap is small.
Rolling Thunder 2
Precise shooting, cover-jumping and timing carry every stage
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.
Rolling Thunder 2
Solo/co-op - enemies follow scripted spawn patterns
Teenage Mutant Ninja Turtles IV: Turtles in Time
Foot Soldiers run fixed scripts.
Rolling Thunder 2 leans a little harder on variance, though the gap is small.
Rolling Thunder 2
Enemy appearances are fixed once memorized
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.
Rolling Thunder 2
Learning spawn points and weapon management is the meta-game
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.