Malstrom explains how he would make his own 2d Mario game

[Old Rock]

And what if you don’t play the game for over a year and have, on that save file, Mushroom World completely conquered and you have to start with a steep uphill challenge?

That's why I got bored with animal crossing after a year since I play games on an irregular schedule. (Which was why I prefer Harvest Moon in terms of my schedule even though AC is more addicting) =P 
"The more the land shifts to being Bowser’s, the more Hammer Brothers begin coming back. If you really want a challenge, don’t play for a long time and come back to that save and face a conquered land!"-Sounds good but Mario isn't really known for its hard enemies. Even on SMB: Lost Levels, it was more focused on the platforming...

Though I agree that about the random weather gameplay in a 2D game since it could be the equivalent to SMG's comets.The Animal Crossing + Mario game is a great idea and would probably be awesome...but I don't agree with most of his ideas.