Oh my god... those melodies... so good... they sound like they're straight out of some SNES game or something. You know what they really remind me of? Stickerbrush Symphony. They've got that really longing melancholic feel to them. And Stickerbrush is like the best vg song ever, so well done.
My only suggestion is that some are a lot better than others. If you clean up the issues I'm about to mention down below it'd be a 9, but if you arranged this properly and cut out the less good melodies it could be a 10.
My favorite melodic points are :35, 2:02, 3:15. This is not an exhaustive list though.
The big problem that I see with this piece is the clash of the melodies and dnb. Like, the melodies are too beautiful and placid to have crazy beats going on under them, and so the two just don't go together well. Normally when I hear dnb songs they either have repetitive energetic melodies or more sinister dark bassy stuff. The melodies in this song are straight out of some happy RPG or something, so I feel like it's not working. The other possible cause of this problem is the actual samples you're using - I feel like they're too meaty and would typically make up a 4 on the floor beat. If you want an example of beats that might work better, listen to this song: http://compo.thasauce.net/files/A_zu_ra_-_Ticking_Time_Bomb(OHC259).mp3 Something like that might have a better shot of fitting into this song (though it'd still have to be slowed down).
The other problem with it, and while it's not as big it's still pretty big, is those panning notes that go through the whole song. I like them initially, but they eventually feel very repetitive. This can *sometimes* work, but I think it's not working here. It may just be a problem of instrumentation - if the instrument was more bassy, it might work better. Also maybe if it was quieter? But I can't really say.
Minor: baseline is too busy at 1:47, kinda clashes with the melody.
Anyway you already know how obsessive I am about melodies so the good news is the hard work is already done! The melodies are great and that makes the song great by default. You just have to put the rest of the song into place.