head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
Loose action execution and horde-building through scripted comedy set-pieces.

Execution · Practiced Mastery
Forgiving web-swinging and rhythm combat across a scripted open city.
Stubbs the Zombie in Rebel Without a Pulse leans Execution (Practiced Mastery); The Amazing Spider-Man leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Stubbs the Zombie in Rebel Without a Pulse
Limb-throwing and horde wrangling need only loose aim
The Amazing Spider-Man
Web-rush traversal and combo timing carry combat
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Stubbs the Zombie in Rebel Without a Pulse
Townsfolk and soldiers follow scripted AI
The Amazing Spider-Man
Villains and thugs follow movie-script patterns
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Stubbs the Zombie in Rebel Without a Pulse
Encounters are fixed set-pieces
The Amazing Spider-Man
Open city events are static templates
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Stubbs the Zombie in Rebel Without a Pulse
Conversion economy - building your horde - rewards light planning
The Amazing Spider-Man
Upgrades and side-mission routing are shallowly solvable
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.