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
Twin-stick co-op shooter precursor.

Optimization · Practiced Mastery
Remake of the original Risk of Rain with new survivors and tighter action.
Helldivers leans Optimization (Practiced Mastery); Risk of Rain Returns 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.
Helldivers
Twin-stick aim and stratagem inputs
Risk of Rain Returns
Platforming and aiming demand sharper inputs than original.
Helldivers leans a little harder on reads, though the gap is small.
Helldivers
Scripted enemies, no real reads
Risk of Rain Returns
Scripted enemy behaviour throughout.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Helldivers
Random spawns and patrol pressure
Risk of Rain Returns
Random item pool defines builds run to run.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Helldivers
Loadout combos and stratagem chains
Risk of Rain Returns
Survivor kits and routing reward optimization.
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.