Bass
One thing that defines drum and bass well is well.. drum and bass. The bass line I feel was written properly but in a good critique you must learn something to help better yourself later. Therefore I will critique on the bass. Like I said the bass line is written great but the sample you used just dosnt move me that much. It works for the beginning great but later make it either more earthy like big drums do, or more sin wave like. I dont know if youll understand that but just test other basses. Im still learning myself but you seem to learn faster than I do. Keep it up!