I'm not really that big a fan of the New Super Mario Bros. series' music in general, but the World 7 map theme in NSMBWii always stuck with me for some reason, so I was super excited to see what you did with it. And I gotta say, I'm definitely not disappointed. Really like what you did with it!
However, in addition to what Latios said, there are a few more noticeable issues:
Mainly, you did not include the full loop of the song in your arrangement. The melody actually plays a second time with slightly different chords towards the end, and then there's an additional segment you completely left out after that. If you listen to the original, the loop actually ends at about 0:54, but you only included the first 23 seconds. In the final section of the song at 0:47, I'd recommend bringing out the other instruments more like the harp and bass, but it's all up to you what you want to include or not. Either way, add those extra sections.Edit:
Oops, didn't read, that's already been said so ignore that lol
Another thing is the chords themselves. For the LH, I'm getting this:
(ignore the terrible 2nd layer spacing for now)
Normally, I'd be fine with this because inverted major 7ths have a weird clashing sound, but since you included the 7th in some chords and not others, I'm not convinced you left them out on purpose.
Other than this though, great arrangement! Glad to see this one finally be arranged.