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

Execution · Practiced Mastery
A maze-chase arcade game testing dodging under a scrolling screen's pressure.

Execution · Practiced Mastery
A classic arcade brawler sending the turtles through time to pummel Foot Clan waves.
Devil World leans Execution (Practiced Mastery); Teenage Mutant Ninja Turtles IV: Turtles in Time 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.
Devil World
Dodging demons while the scrolling maze crushes you is twitch
Teenage Mutant Ninja Turtles IV: Turtles in Time
Throw timing, positioning, and boss dodges are the whole test.
Teenage Mutant Ninja Turtles IV: Turtles in Time leans a little harder on reads, though the gap is small.
Devil World
Demons chase on simple fixed logic
Teenage Mutant Ninja Turtles IV: Turtles in Time
Foot Soldiers run fixed scripts.
Devil World leans a little harder on variance, though the gap is small.
Devil World
Scroll direction shifts add mild unpredictability
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.
Devil World
Maze routes and cross timing are learnable patterns
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.