In recent news, Nintendo has revealed that it is teaming with Illumination in order to create a new Super Mario movie. This will be the first U.S. Theatrical film released after the 1993 live action film starring the late Bob Hoskins and John Leguizamo. Of course this film is going to have a stronger resemblance to the games given that it is going to be animated. The other film that was released in 1993 bore very little resemblance to the games. As a matter of fact, the environment of the mushroom kingdom looked more like something out of Batman or Blade Runner than any Mario game.
Even though many people remember the 1993 film as the first attempt at an adaptation, that was not the first one. An earlier animated film was released in Japan which had a lot of resemblance to the games. The characters resembled their video game counterparts. When people compare that to Bowser being pretty much human in the 1993 film, this shows that the producers cared about the source material at the time.
As of right now, there is no telling what the film is going to look like when it comes out. The only thing that can be said is that it is probably going to look identical to the recent games given that video game technology has caught up to the other forms of technology. All that would be needed would be for someone to play a game and then have them voiced by big name actors. However, it is very likely that Nintendo and Illumination are going to work on a story that is going to work well for the audience.