head to head
Song of the Deep asks more than Red Dead Redemption 2, and the gap is optimization.

Execution · Practiced Mastery
A cinematic open-world western leaning on shooting feel and atmosphere.

Optimization · Practiced Mastery
A storybook underwater metroidvania about a girl piloting a homemade submarine to find her father.
Red Dead Redemption 2 leans Execution (Practiced Mastery); Song of the Deep leans Optimization (Practiced Mastery).
Red Dead Redemption 2 leans a little harder on execution, though the gap is small.
Red Dead Redemption 2
Gunplay and Dead Eye reward aim and timing.
Song of the Deep
Gentle submarine handling and claw manipulation
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Red Dead Redemption 2
Enemies use scripted AI patterns, not adaptation.
Song of the Deep
Scripted sea creatures
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Red Dead Redemption 2
Some hunting and weather randomness, lightly hidden.
Song of the Deep
Unknown undersea map first dive
Song of the Deep leans clearly harder on optimization.
Red Dead Redemption 2
Loadouts and routes solvable but loose.
Song of the Deep
Environmental puzzles and upgrade routing carry the game
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.