head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Optimization · Practiced Mastery
A first-person Metroid adventure spanning planets, steered with the Wii's motion-aimed cannon.

Optimization · Practiced Mastery
The PS3 debut of Ratchet & Clank, mixing exotic weapons with an upgrade-driven adventure.
Metroid Prime 3: Corruption leans Optimization (Practiced Mastery); Ratchet & Clank Future: Tools of Destruction leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid Prime 3: Corruption
Pointer aiming and Hypermode management in fights.
Ratchet & Clank Future: Tools of Destruction
Third-person shooting and platforming, moderately demanding
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid Prime 3: Corruption
Scripted bosses and pirates.
Ratchet & Clank Future: Tools of Destruction
Scripted enemy waves
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid Prime 3: Corruption
Deterministic worlds.
Ratchet & Clank Future: Tools of Destruction
Deterministic encounters
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid Prime 3: Corruption
Scanning, sequencing, and multi-planet routing drive progress.
Ratchet & Clank Future: Tools of Destruction
Weapon levelling economy and upgrade pathing
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.
full breakdown
Metroid Prime 3: Corruption →
full breakdown
Ratchet & Clank Future: Tools of Destruction →