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 run-and-gun arcade shooter that is almost pure twitch execution.

Execution · Pure Mechanics
A brutally fast endless runner that is pure twitch reflex execution.
Metal Slug 5 leans Execution (Pure Mechanics); Velocibox leans Execution (Pure Mechanics).
Velocibox leans a little harder on execution, though the gap is small.
Metal Slug 5
precise dodge/shoot run-and-gun demands
Velocibox
Twitch reflexes at extreme speed are the entire game
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Slug 5
enemy waves are fully scripted patterns
Velocibox
No opponent to predict in this solo runner
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
Velocibox
Obstacle patterns are fixed and rapidly memorized
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Slug 5
weapon pickup and route memorization
Velocibox
Memorizing patterns helps but reflex execution dominates
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.