Back in 1993, Hollywood made an attempt to turn the Super Mario Bros. into a feature film. The movie had... problems. It's generally viewed as one of the worst adaptations of a medium that has never been particularly successful in making the jump to the big screen. Nintendo became more than a little nervous about letting any of its popular characters get the film treatment after that.
However, now the Super Mario Bros. are on their way back to the big screen thanks to the folks at Illumination Entertainment. The studio behind Despicable Me is confident this new attempt will succeed where the last one failed because Nintendo itself is working on this one, in the form of Mario creator Shigeru Miyamoto working with the studio behind the scenes. Knowing that, I'm starting to actually look forward to this new movie and beginning to think about what elements from the franchise I'd like to see in a Super Mario Bros. movie.
This may go without saying, but just to make things clear, this needs to be a Super Mario BROTHERS movie, not simply a Super Mario movie, and that means it needs to include Luigi as well as Mario. Neither character should be the hero with the other playing the sidekick. The movie needs to focus on the pair of them equally. It can use a standard buddy cop format with one of them being a strong comic character, but not at their expense. Mario and Luigi are brothers and partners, and they should share the stage.
The Mushroom Kingdom
A proper Super Mario Bros. movie requires the proper setting, and that only means one place: the Mushroom Kingdom. Most of the previous Super Mario Bros. movie took place in this weird dystopian alternate dimension. It was all darkness and metal, and looked nothing like the Mushroom Kingdom that fans of the games would know. While certainly the new movie won't be all sunshine and rainbows, it should include sunshine and rainbows, as those are frequent elements in the games. The Mushroom Kingdom is a happy place that maybe just isn't going through a very happy time, and we need to see that in the film.
A movie that takes place in the Mushroom Kingdom must obviously include the people who live in that land, or more specifically, the leader. Peach is the primary female character of the Mario Bros. games, and the movie certainly needs some gender diversity. While she's frequently a damsel in distress, and saving her is the ultimate point of many of the titles, she also been a sidekick and worked alongside our heroes on more than one occasion. It would be great to see her as more than simply a kidnapped princess/love interest, but ultimately we just need to have her in the movie one way or another.
A Better Bowser
Depending on your perspective, Dennis Hopper's performance as King Koopa in the original Super Mario Bros. movie is either the best or worst part of the film. Hopper goes all in and the performance is suitably bonkers, but what the new movie needs is a more traditional version of the character. One that is more a giant fire-breathing turtle and less a human with a really weird tongue. Bowser needs to be a proper monster, and really, an animated film is the only way to make that work. The floating clown car is optional.
No single object in the Mario games is as iconic as the Super Mushroom. In the original Super Mario Bros. and most of the direct sequels, it's the first item that causes Mario to grow, which also makes him slightly less vulnerable. In an animated film, we could actually see the mushroom play its intended purpose and make Mario grow. Otherwise, it could be used for pretty much any other reason the plot requires. As long as it's there, we're good.
The Koopa Kids
One of the more entertaining additions to the Super Mario Bros. games over the years was the addition of the Koopa Kids. These young Koopas were all named after musicians and have wildly different looks. This led to the creation of fun personalities for the characters in places like the Super Mario Bros. animated series that have come out over the years. They would be great additions to any film. They could add depth to the antagonist side of things, giving the Mario Bros. more things to overcome. They could also add some comic relief.
Every good hero needs a sidekick, and for Mario, that's Yoshi. His dinosaur pal can eat pretty much anything, and some of those things give him special abilities. The live action movie gave us a little dino character they called Yoshi, but if you can't ride him like a horse, then he's not really Yoshi. While Yoshi should be a sidekick/steed in the animated movie, the character himself has grown over the years, so that doesn't mean he has to be lacking personality. Yoshi can still be a character in own right while also helping Mario navigate the difficulties of the Mushroom Kingdom.
While Mario and his brother Luigi may have made their name thanks to a series of side-scrolling platform games, the brothers have expanded their horizons over the years, and no associated Mario title may be quite as well loved as the Mario Kart series. It would be awesome to get some sort of nod to the Mario Kart series by letting the characters get behind the wheel at some point. It doesn't have to be a major "racing" sequence, though I wouldn't say no to that, it can just be a fun easter egg-type reference for the fans. But a spinoff movie down the road would be great too.
The primary mechanic of all of Mario's adventures is platform jumping. As such, the element needs to be a major part of any Super Mario Bros. movie. It could be worked into the story by borrowing an element from Edgar Rice Burroughs John Carter stories. Maybe gravity is different in the Mushroom Kingdom, which means that the Mario Bros., being from Earth, can now jump much higher and further than they could at home. In fact, in a lot of ways the premise of Princess of Mars would work as a starting point for a Mario Bros. movie plot. Maybe it would work better than John Carter actually did.