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
A cartoonish horde shooter sequel of planet-hopping monster massacres.

Execution · Practiced Mastery
Day-glo traversal shooter where staying on rails and walls keeps your style and survival up.
Serious Sam 2 leans Execution (Practiced Mastery); Sunset Overdrive 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.
Serious Sam 2
Sustained horde-clearing aim and strafing
Sunset Overdrive
Grind-rail momentum and mid-air shooting reward clean hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Serious Sam 2
Enemy waves are entirely scripted
Sunset Overdrive
Mutant hordes are pattern-driven, never adaptive
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Serious Sam 2
Cartoon set-pieces surprise once
Sunset Overdrive
Horde mode spawns mix things up slightly
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Serious Sam 2
Target priority and arena routes are learnable
Sunset Overdrive
Amp builds, traversal lines, and style multipliers are 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.