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

Execution · Pure Mechanics
A first-person endless runner testing reflexes on a doomed spaceship.

Execution · Pure Mechanics
An arcade test of jump timing and enemy-flipping precision on a single screen.
Infinity Runner leans Execution (Pure Mechanics); Mario Bros. 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.
Infinity Runner
Fast reflexes for dodging and QTEs define play
Mario Bros.
Precise jumps and bump timing under crowding enemies decide survival
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Infinity Runner
Scripted obstacles, no adaptive opponent
Mario Bros.
Versus mode adds light human interference, enemies are scripted
Infinity Runner leans a little harder on variance, though the gap is small.
Infinity Runner
Some procedural obstacle variation
Mario Bros.
Enemy spawns vary slightly but patterns are quickly learned
Mario Bros. leans a little harder on optimization, though the gap is small.
Infinity Runner
Little to solve beyond reaction memorization
Mario Bros.
POW block usage and enemy routing have known best lines
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.