I'd make a 2v2 mini-game where each team would have to successfully race their way to the top of a mountain in 60 seconds or less. Both teams would be equipped with rope and power gloves. One teammate would wear the power gloves to throw the other teammate upwards to a higher ledge, while the teammate who who is being thrown would tie the rope to a nearby hook (that just so happened to be stuck into the mountain wall [because it's Mario Party xD]), throw the rope downward, and pull the other teammate up. On rare occasion any of the hooks will come loose as the rope is tied, so the teammate on top will have to hold the hook in place as the other teammate manually climbs up the rope (which is slower than being pulled up). Minigame obstacles would include Falling Boulders - Falling Boulders would push the player above off, making them descend one mountain ledge downward; and Shy Guys - Shy Guys would come out of nowhere and untie and steal the rope, temporarily rendering a team unable to proceed until a Lakitu throws another rope their way several seconds later. Of course, first person to make it up the mountain or the team who has the highest progression in altitude, wins.
I hope that all made sense lol.