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
Top-down aim and kiting against scripted alien swarms with light upgrade planning.

Execution · Practiced Mastery
The infamous, glitch-ridden 2006 Sonic reboot where the physics are the real boss.
Shadowgrounds leans Execution (Practiced Mastery); Sonic the Hedgehog (2006) 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.
Shadowgrounds
Kiting alien swarms top-down rewards steady aim and movement
Sonic the Hedgehog (2006)
Fighting unreliable physics demands constant correction
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Shadowgrounds
Aliens charge on simple scripts, never modelling you
Sonic the Hedgehog (2006)
No adaptive opposition
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Shadowgrounds
Ambush triggers are scripted-but-unknown on first playthrough
Sonic the Hedgehog (2006)
Bugs make outcomes partly unpredictable
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Shadowgrounds
Weapon upgrade routing is a light solvable layer
Sonic the Hedgehog (2006)
Learning which routes the jank permits
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.