head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Pure Mechanics
Combo execution and dodge timing through scripted grindhouse brawls.

Execution · Pure Mechanics
A classic beat-em-up demanding execution against scripted enemy waves.
Shank leans Execution (Pure Mechanics); Teenage Mutant Ninja Turtles III: The Manhattan Project 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.
Shank
Combo juggling and dodge timing carry every brawl
Teenage Mutant Ninja Turtles III: The Manhattan Project
beat-em-up timing and enemy juggling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Shank
Enemies and bosses attack on fixed patterns
Teenage Mutant Ninja Turtles III: The Manhattan Project
enemies run simple fixed scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Shank
Hand-built levels with no randomness
Teenage Mutant Ninja Turtles III: The Manhattan Project
minor enemy spawn randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Shank
Weapon-swap combo routing rewards some lab work
Teenage Mutant Ninja Turtles III: The Manhattan Project
character choice and route memorization
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.