head to head
World War Z: Aftermath asks more than Grand Theft Auto: San Andreas, and the gap is execution.

Optimization · Practiced Mastery
A sprawling open-world crime epic with RPG-style character stats across a whole state.

Execution · Practiced Mastery
Co-op horde shooting that tests sustained aim and defensive setup planning.
Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery); World War Z: Aftermath leans Execution (Practiced Mastery).
World War Z: Aftermath leans clearly harder on execution.
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
World War Z: Aftermath
Horde shooting and melee timing carry every swarm
World War Z: Aftermath leans a little harder on reads, though the gap is small.
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
World War Z: Aftermath
Zombies are pathfinding scripts, not minds
World War Z: Aftermath leans a little harder on variance, though the gap is small.
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
World War Z: Aftermath
Spawn director shuffles hordes mildly between runs
Grand Theft Auto: San Andreas leans a little harder on optimization, though the gap is small.
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
World War Z: Aftermath
Class builds, defenses and weapon upgrades 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.