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.

Execution · Twitch Chaos
A kart racer where item luck collides with optimized lines and builds.

Execution · Twitch Chaos
Bullet-hell roguelike third-person shooter.
Mario Kart 8 Deluxe leans Execution (Twitch Chaos); Returnal leans Execution (Twitch Chaos).
Returnal leans a little harder on execution, though the gap is small.
Mario Kart 8 Deluxe
Drift boosts, snaking, and item timing demand precision.
Returnal
Bullet-hell dodge and aim under pressure
Mario Kart 8 Deluxe leans a little harder on reads, though the gap is small.
Mario Kart 8 Deluxe
Human racers bait and block items but mostly reactive.
Returnal
Bosses scripted, patterns not adaptive
Returnal leans a little harder on variance, though the gap is small.
Mario Kart 8 Deluxe
Item distribution heavily randomized by position.
Returnal
Room layouts, parasites, items roguelike
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Mario Kart 8 Deluxe
Kart build, line, and shortcut knowledge define top times.
Returnal
Build synergies and route planning
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.