head to head
Prototype 2 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
An open-world revenge tale where a new shapeshifter hunts Alex Mercer through plague-zoned New York.
Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery); Prototype 2 leans Execution (Practiced Mastery).
Prototype 2 leans clearly harder on execution.
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
Prototype 2
Power-swapping combat and traversal demand decent dexterity
Prototype 2 leans a little harder on reads, though the gap is small.
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
Prototype 2
Blackwatch and infected never adapt
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
Prototype 2
Sandbox encounters carry slight randomness
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
Prototype 2
Mutation upgrades and target-hunting routes 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.