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.

Optimization · Practiced Mastery
The N64 collectathon that buries five playable Kongs in collectibles.

Optimization · Practiced Mastery
A mining metroidvania about digging efficient tunnels, hauling ore, and compounding upgrades.
Donkey Kong 64 leans Optimization (Practiced Mastery); SteamWorld Dig 2 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.
Donkey Kong 64
Moderate platforming and minigame dexterity
SteamWorld Dig 2
Light platforming and digging dexterity
SteamWorld Dig 2 leans a little harder on reads, though the gap is small.
Donkey Kong 64
Scripted bosses and enemies
SteamWorld Dig 2
Scripted enemies only
SteamWorld Dig 2 leans a little harder on variance, though the gap is small.
Donkey Kong 64
Little randomness; secrets known once found
SteamWorld Dig 2
Procedural ore pockets add mild run-to-run unknowns
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Donkey Kong 64
Routing five Kongs through collectible checklists
SteamWorld Dig 2
Dig routing, resource economy, and upgrade ordering are 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.