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

Execution · Practiced Mastery
A vertical scrolling shooter about upgrading your ship between bullet-hell missions.

Execution · Practiced Mastery
A cartoonish horde shooter sequel of planet-hopping monster massacres.
Raptor: Call of the Shadows leans Execution (Practiced Mastery); Serious Sam 2 leans Execution (Practiced Mastery).
Raptor: Call of the Shadows leans a little harder on execution, though the gap is small.
Raptor: Call of the Shadows
dodging bullet patterns needs quick reflexes
Serious Sam 2
Sustained horde-clearing aim and strafing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Raptor: Call of the Shadows
scripted enemy waves, no adaptation
Serious Sam 2
Enemy waves are entirely scripted
Raptor: Call of the Shadows leans a little harder on variance, though the gap is small.
Raptor: Call of the Shadows
random shop upgrades between missions
Serious Sam 2
Cartoon set-pieces surprise once
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Raptor: Call of the Shadows
ship build and upgrade optimization
Serious Sam 2
Target priority and arena routes are learnable
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.