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
Raw paddle reflexes keeping a bouncing clown alive against balloon rows.

Execution · Pure Mechanics
A classic 2D Mario platformer rewarding tight jump execution above all.
Circus Atari leans Execution (Pure Mechanics); New Super Mario Bros. U Deluxe 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.
Circus Atari
Paddle precision under the falling clown is everything
New Super Mario Bros. U Deluxe
precise jump and platforming execution
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Circus Atari
No opponent - pure physics reaction
New Super Mario Bros. U Deluxe
fixed enemy patterns, no adaptation
Circus Atari leans a little harder on variance, though the gap is small.
Circus Atari
Bounce angles add slight unpredictability
New Super Mario Bros. U Deluxe
minor enemy placement randomness
New Super Mario Bros. U Deluxe leans a little harder on optimization, though the gap is small.
Circus Atari
Balloon-row targeting strategy is thin but present
New Super Mario Bros. U Deluxe
level routing for speed/collectibles
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.