head to head
Neither is simply harder - they are hard in different places. Grand Theft Auto V demands more reads; Have a Nice Death demands more execution.

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

Execution · Practiced Mastery
A slick action roguelite where execution under demanding boss patterns is the decisive skill.
Grand Theft Auto V leans Execution (Practiced Mastery); Have a Nice Death leans Execution (Practiced Mastery).
Have a Nice Death leans clearly harder on execution.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Have a Nice Death
Stylish fast-paced combat demands precise timing and weapon switching
Grand Theft Auto V leans clearly harder on reads.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Have a Nice Death
Boss attacks are choreographed and learnable; no adaptive enemy
Have a Nice Death leans clearly harder on variance.
Grand Theft Auto V
Some mission and lobby randomness.
Have a Nice Death
Curse and relic drops randomise each department run's power curve
Have a Nice Death leans clearly harder on optimization.
Grand Theft Auto V
Heists, money loops, builds learnable.
Have a Nice Death
Weapon synergies and curse selection reward consistent knowledge of the system
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.