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.

Variance · Systems & Chaos
The harder sequel that swaps doors for a mask and forces a frantic multitasking routine against more animatronics.

Optimization · Practiced Mastery
A S.T.A.L.K.E.R. prequel adding a dynamic faction war across the Zone.
Five Nights at Freddy's 2 leans Variance (Systems & Chaos); S.T.A.L.K.E.R.: Clear Sky leans Optimization (Practiced Mastery).
S.T.A.L.K.E.R.: Clear Sky leans a little harder on execution, though the gap is small.
Five Nights at Freddy's 2
Mask, flashlight, and music box juggling demands fast hands
S.T.A.L.K.E.R.: Clear Sky
Punishing gunfights and anomaly navigation
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Five Nights at Freddy's 2
RNG-driven animatronics, not adaptive opponents
S.T.A.L.K.E.R.: Clear Sky
Faction-war AI is systemic, not adaptive to you
Five Nights at Freddy's 2 leans a little harder on variance, though the gap is small.
Five Nights at Freddy's 2
More stalkers, more hidden movement rolls
S.T.A.L.K.E.R.: Clear Sky
Dynamic faction war and emission RNG hide outcomes
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Five Nights at Freddy's 2
Optimal check rotations make late nights solvable
S.T.A.L.K.E.R.: Clear Sky
Upgrade economy and territory routing reward planning
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.