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
A top-down war shooter testing dodging and aim through scripted enemy waves.

Execution · Pure Mechanics
Reflex-driven point-to-point racing through heavily scripted setpieces.
Iron Tank: The Invasion of Normandy leans Execution (Pure Mechanics); Need for Speed: The Run 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.
Iron Tank: The Invasion of Normandy
Dodging fire and aiming under the scrolling assault is constant
Need for Speed: The Run
Reaction driving through traffic and setpieces is the test
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Iron Tank: The Invasion of Normandy
Enemies spawn on fixed scripts, no adaptation
Need for Speed: The Run
Rivals rubber-band on scripts, nothing to out-think
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Iron Tank: The Invasion of Normandy
Some enemy placement surprises but levels are fixed
Need for Speed: The Run
Scripted events surprise once, then are known
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Iron Tank: The Invasion of Normandy
Weapon powerup management and routing help survival
Need for Speed: The Run
Checkpoint routes and car choice are quickly solved
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.