This isn't exactly drum'n'base. It has some of its facettes, but too many things aren't right. It also has some jungle in it. In fact, its more jungle than d'n'b. True d'n'b doesn't have an intro like this, it starts with the drums so DJ's can mix the song in. The focus is more on the drums and the base, but mixing could be the fault here too.
Your melody is pretty complex for d'n'b too which takes away focus from its genre.
The song itself isn't bad perse, but as I'n a d'n'b lover, it makes me wanna stop listening. I kinda expected some d'n'b and got disappointed.