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 · Pure Mechanics
A run-and-gun arcade shooter that is almost pure twitch execution.

Execution · Pure Mechanics
A tilt-control balance game about rolling precisely through floating mazes.
Metal Slug 5 leans Execution (Pure Mechanics); Super Monkey Ball 3D 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.
Metal Slug 5
precise dodge/shoot run-and-gun demands
Super Monkey Ball 3D
Precise tilt control under gravity is the entire test
Super Monkey Ball 3D leans a little harder on reads, though the gap is small.
Metal Slug 5
enemy waves are fully scripted patterns
Super Monkey Ball 3D
Solo stages, no opponent to predict
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Slug 5
minor drop and spawn randomness
Super Monkey Ball 3D
Levels are fixed with little randomness
Super Monkey Ball 3D leans a little harder on optimization, though the gap is small.
Metal Slug 5
weapon pickup and route memorization
Super Monkey Ball 3D
Optimal lines through mazes reward route learning
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.