head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Practiced Mastery
Helicopter handling under fire while routing fuel and ammo across fixed missions.

Optimization · Practiced Mastery
Time-manipulation puzzles meet the series' signature weapon-upgrade gunplay.
Desert Strike: Return to the Gulf leans Execution (Practiced Mastery); Ratchet & Clank: A Crack in Time leans Optimization (Practiced Mastery).
Desert Strike: Return to the Gulf leans a little harder on execution, though the gap is small.
Desert Strike: Return to the Gulf
Helicopter inertia and dodging fire demand real stick control
Ratchet & Clank: A Crack in Time
Hoverboot movement, aiming, and time-puzzle dexterity.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Desert Strike: Return to the Gulf
Defenses are fixed emplacements, nothing adapts
Ratchet & Clank: A Crack in Time
Entirely scripted single-player content.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Desert Strike: Return to the Gulf
Maps are unknown on first sortie only
Ratchet & Clank: A Crack in Time
First-pass unknowns in puzzles and arenas.
Ratchet & Clank: A Crack in Time leans a little harder on optimization, though the gap is small.
Desert Strike: Return to the Gulf
Fuel, ammo and mission-order routing is the strategic core
Ratchet & Clank: A Crack in Time
Clank's time puzzles and weapon economy are solvable systems.
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.