I'm liking where this is going so far.

Few things to note (and some are just personal preference):
In the drop, your mixdown is very cluttered- you could definitely do without so much going on in the highs/high mids. Almost sounds like there's white noise in the background constantly.
Another thing about the drop (and in general really) is that your drums aren't coming through all too well (up until the second drop, that's where they start to fit). I feel like they could stand out a bit more.
Your lead is quite high pitched, so those parts where you raise the melody by an octave actually hurt to listen to.
Another thing that I wasn't fond of was the noise that happened on the 4th beat of (nearly) every measure in the drop- it just made it sound kind of sloppy.

On a positive note, your composition is fantastic and your drum samples fit very well. Once the mixdown is cleaned up I can see myself enjoying this song a lot.

try using an LFO or an envelloppe to make it pitch down. (like a real 808)