Hey Spring Tyano! I compose on MuseScore myself so it's always cool to hear what other MuseScore composers are doing. Absolutely loved the variety you went for! My favs were definitely "Dear Mr. Tuna" and "Where Isda Muzik?".
I don't have too many complaints about your compositions, although your last piece, as gorgeous as it was, was a little distorted due to volume clipping by the mix. I've had this problem before, and to get around it, I would use Audacity to lower the amplification and compress the track up to volume as needed (the final mix should usually be no higher than -3dB to avoid clipping), there may some tutorials online you can look up as to how to compress and adjust your audio volumes. Or, you can also lower the master volume in the score mixer before exporting and compress or amplify it in Audacity if needed.
Great work, keep it up!