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

Execution · Practiced Mastery
Strategic dismemberment under resource pressure, solved by upgrade planning and practiced limb-aiming.

Execution · Practiced Mastery
An over-the-top horde shooter throwing hundreds of charging enemies at you.
Dead Space (2008) leans Execution (Practiced Mastery); Serious Sam: The Second Encounter 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.
Dead Space (2008)
Precise limb-targeting under Necromorph pressure is the core skill
Serious Sam: The Second Encounter
Circle-strafing huge horde waves tests stamina and aim
Dead Space (2008) leans a little harder on reads, though the gap is small.
Dead Space (2008)
Necromorphs follow fixed approach patterns, not player modelling
Serious Sam: The Second Encounter
Enemies charge in fixed patterns
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dead Space (2008)
Store stock is deterministic; minor drop variance on kills
Serious Sam: The Second Encounter
Wave compositions memorised after one run
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Dead Space (2008)
Weapon upgrading, power-node routing and stasis timing are optimisable
Serious Sam: The Second Encounter
Prioritising targets and managing arenas is 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.