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

Optimization · Practiced Mastery
A sprawling open-world crime epic with RPG-style character stats across a whole state.

Optimization · Practiced Mastery
A mining metroidvania about digging efficient tunnels, hauling ore, and compounding upgrades.
Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery); SteamWorld Dig 2 leans Optimization (Practiced Mastery).
SteamWorld Dig 2 leans a little harder on execution, though the gap is small.
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
SteamWorld Dig 2
Light platforming and digging dexterity
SteamWorld Dig 2 leans a little harder on reads, though the gap is small.
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
SteamWorld Dig 2
Scripted enemies only
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
SteamWorld Dig 2
Procedural ore pockets add mild run-to-run unknowns
SteamWorld Dig 2 leans a little harder on optimization, though the gap is small.
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
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.