head to head
Halo 3: ODST 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
Moody Halo side story about ordinary troopers piecing together a night in New Mombasa.
Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery); Halo 3: ODST leans Execution (Practiced Mastery).
Halo 3: ODST leans clearly harder on execution.
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
Halo 3: ODST
Squishier soldier demands careful aim and positioning
Halo 3: ODST leans a little harder on reads, though the gap is small.
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
Halo 3: ODST
Covenant patrols are scripted, not adaptive
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
Halo 3: ODST
Open Mombasa hides clues until found
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
Halo 3: ODST
Firefight wave knowledge and route 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.