I've done all the challenges now apart from the multiplayer ones so I can give some more detailed advice about some of the challenges.
Also I've done these.
Ok lets get to the advice you all want to know.
Duck Hunt Duo - Win the final round without being KO'd
Ganondorf - As Ganondorf...
I actually dislike the challenges that are so hard only a small percentage of the playerbase will ever complete them because Sakurai banned hammer use on them. On the whole Ultimate doesn't have these. I guess each to their own. Sakurai will never please everyone all of the time.
Also thank...
Note well you also get a bonus for completing each entire page of challenges.
Also you don't have to do the channelges with a certain character unless the challenge description specifically says to.
Also when the description says a specific level of CPU, you must use that exact level. Any other...