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

Execution · Practiced Mastery
Linear sci-fi shooting plus spatial puzzles with fixed solutions.

Execution · Practiced Mastery
The first cinematic treasure-hunting adventure of cover shootouts and cliffside climbing.
Prey leans Execution (Practiced Mastery); Uncharted: Drake's Fortune 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.
Prey
Standard FPS aim with portal disorientation added
Uncharted: Drake's Fortune
Cover gunfights and climbing timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Prey
Alien enemies follow fixed scripts
Uncharted: Drake's Fortune
Mercenary AI is scripted waves
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Prey
Linear campaign with little randomness
Uncharted: Drake's Fortune
Fully authored set pieces
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Prey
Portal and gravity puzzles have fixed solutions
Uncharted: Drake's Fortune
Encounter layouts and weapon choices are 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.