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

Execution · Practiced Mastery
First-person horror thriller built on brutal improvised-weapon melee.

Optimization · Practiced Mastery
The most polished S.T.A.L.K.E.R., a freeform survival shooter around Pripyat.
Condemned: Criminal Origins leans Execution (Practiced Mastery); S.T.A.L.K.E.R.: Call of Pripyat leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Condemned: Criminal Origins
Visceral melee blocking and counter timing
S.T.A.L.K.E.R.: Call of Pripyat
Deliberate gunplay against mutants and stalkers
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Condemned: Criminal Origins
Enemies ambush but follow simple scripts
S.T.A.L.K.E.R.: Call of Pripyat
A-Life simulation doesn't counter-adapt to you
S.T.A.L.K.E.R.: Call of Pripyat leans a little harder on variance, though the gap is small.
Condemned: Criminal Origins
Unpredictable ambushes on a first playthrough
S.T.A.L.K.E.R.: Call of Pripyat
Emissions, artifact spawns, and mutant encounters are random
S.T.A.L.K.E.R.: Call of Pripyat leans a little harder on optimization, though the gap is small.
Condemned: Criminal Origins
Weapon choice and level knowledge converge
S.T.A.L.K.E.R.: Call of Pripyat
Detector use, upgrades, and quest routing converge
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.