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

Execution · Practiced Mastery
A cinematic side-scrolling shooter about a revolutionary chicken commando.

Execution · Practiced Mastery
The acclaimed cinematic action sequel famous for its train and collapsing-building set pieces.
Rocketbirds: Hardboiled Chicken leans Execution (Practiced Mastery); Uncharted 2: Among Thieves 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.
Rocketbirds: Hardboiled Chicken
platforming and shooting precision needed
Uncharted 2: Among Thieves
Set-piece gunplay and traversal under fire
Uncharted 2: Among Thieves leans a little harder on reads, though the gap is small.
Rocketbirds: Hardboiled Chicken
scripted enemy AI, not adaptive
Uncharted 2: Among Thieves
Campaign AI is scripted; MP adds a trace
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Rocketbirds: Hardboiled Chicken
minimal randomness
Uncharted 2: Among Thieves
Authored spectacle, nothing hidden
Uncharted 2: Among Thieves leans a little harder on optimization, though the gap is small.
Rocketbirds: Hardboiled Chicken
level routing and weapon use
Uncharted 2: Among Thieves
Encounter knowledge trivializes replays
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.