Looked at and listened to your Mario Kart Super Circuit Bowser's Castle one and found these:
The tonality of this theme is a little weird: despite the E minor-like atmosphere, G sharp is prominent, so I suspect Phrygian Dominant-like flavour in the original. As a result, I'd much rather change all A flats in your arrangement to G sharps.
I'm getting the first half of the bassline of Bar 1 as G# (for a half note, all running 16th notes) in the original. The rest of your bassline for Bar 1 is fine and I'd keep the first half of the bassline in that style, but the notes need to change for the first half note.
I'm getting the first half of the right hand of Bar 31 as 8th rest-D-E-G# (all notes are 8th notes) in the original - in fact, they're the same as the melody of the first half of Bar 29.
I'm getting straight 8th notes for the first set of melody D's in Bar 37 in the original instead of your dotted quarter note. I'd like that dotted quarter note split into 8th notes (the span is a bit painful, I know, so I'm letting you off for melody articulations there).
We are going to have to do something about that severe overlap between left and right hands for the first half of your arrangement (Bars 1-17) and Bars 31-32. It sounds surprisingly OK in your arrangement, possibly because you emphasize the melody notes in the MUS, but we might have to cut out all harmony notes in Bars 1-17 above melody notes, accent melody notes only in your arrangement (including in unintuitive places), drop the accompaniment of Bars 31-32 (either drop an octave or drop only the E's an octave), or something like that.
Hey, thanks! I'll be sure to clean these up before I submit.