head to head
Dead Space (2008) asks more than Grand Theft Auto: San Andreas, and the gap is execution.

Execution · Practiced Mastery
Strategic dismemberment under resource pressure, solved by upgrade planning and practiced limb-aiming.

Optimization · Practiced Mastery
A sprawling open-world crime epic with RPG-style character stats across a whole state.
Dead Space (2008) leans Execution (Practiced Mastery); Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery).
Dead Space (2008) leans clearly harder on execution.
Dead Space (2008)
Precise limb-targeting under Necromorph pressure is the core skill
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
Dead Space (2008) leans a little harder on reads, though the gap is small.
Dead Space (2008)
Necromorphs follow fixed approach patterns, not player modelling
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dead Space (2008)
Store stock is deterministic; minor drop variance on kills
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Dead Space (2008)
Weapon upgrading, power-node routing and stasis timing are optimisable
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
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.