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 party racing game about rolling Kirby to collect the most strawberries.

Execution · Twitch Chaos
N64 couch classic where blue shells and shortcuts decide friendships.
Kirby's Dream Buffet leans Execution (Twitch Chaos); Mario Kart 64 leans Execution (Twitch Chaos).
Mario Kart 64 leans a little harder on execution, though the gap is small.
Kirby's Dream Buffet
Rolling and dodging on courses needs decent control
Mario Kart 64
Mini-turbo snaking and shortcut execution
Mario Kart 64 leans a little harder on reads, though the gap is small.
Kirby's Dream Buffet
Human racers add light prediction but items dominate
Mario Kart 64
Couch rivals bait shells and fakes
Mario Kart 64 leans a little harder on variance, though the gap is small.
Kirby's Dream Buffet
Item pickups and course chaos swing outcomes
Mario Kart 64
Item draws swing every race
Mario Kart 64 leans a little harder on optimization, though the gap is small.
Kirby's Dream Buffet
Knowing shortcuts and ability use helps modestly
Mario Kart 64
Shortcut and line knowledge is fully mapped
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.