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

Execution · Practiced Mastery
Cave's gothic horizontal bullet hell with player-chosen stage difficulty and item-chain scoring.

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.
Deathsmiles leans Execution (Practiced Mastery); Grand Theft Auto V leans Execution (Practiced Mastery).
Deathsmiles leans clearly harder on execution.
Deathsmiles
Horizontal bullet dodging with dual-direction shooting
Grand Theft Auto V
Driving and shooting demand decent inputs.
Grand Theft Auto V leans clearly harder on reads.
Deathsmiles
Scripted gothic enemies never adapt
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.
Deathsmiles
Selectable difficulty fixes patterns, little randomness
Grand Theft Auto V
Some mission and lobby randomness.
Deathsmiles leans clearly harder on optimization.
Deathsmiles
Item counter and rank route choices drive scoring
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.