head to head
Grand Theft Auto V asks more than Ratchet & Clank: Size Matters, and the gap is reads.

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.

Execution · Practiced Mastery
A handheld Ratchet & Clank adventure shrunk down for PSP with armour collecting.
Grand Theft Auto V leans Execution (Practiced Mastery); Ratchet & Clank: Size Matters leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Ratchet & Clank: Size Matters
Run-and-gun platforming on PSP controls
Grand Theft Auto V leans clearly harder on reads.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Ratchet & Clank: Size Matters
Enemies are scripted
Grand Theft Auto V leans a little harder on variance, though the gap is small.
Grand Theft Auto V
Some mission and lobby randomness.
Ratchet & Clank: Size Matters
Fixed levels and drops
Ratchet & Clank: Size Matters leans a little harder on optimization, though the gap is small.
Grand Theft Auto V
Heists, money loops, builds learnable.
Ratchet & Clank: Size Matters
Weapon upgrades and armour-set collecting
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.