head to head
Grand Theft Auto V asks more than Costume Quest, and the gap is execution.

Optimization · Practiced Mastery
A charming kid-friendly RPG with timing prompts and light costume strategy.

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.
Costume Quest leans Optimization (Practiced Mastery); Grand Theft Auto V leans Execution (Practiced Mastery).
Grand Theft Auto V leans clearly harder on execution.
Costume Quest
Timed button prompts are the only dexterity ask
Grand Theft Auto V
Driving and shooting demand decent inputs.
Grand Theft Auto V leans clearly harder on reads.
Costume Quest
Monster battles follow simple fixed scripts
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Grand Theft Auto V leans a little harder on variance, though the gap is small.
Costume Quest
Quest content is fixed once doors are knocked
Grand Theft Auto V
Some mission and lobby randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Costume Quest
Costume ability matchups and stamp choices are light strategy
Grand Theft Auto V
Heists, money loops, builds learnable.
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.