This has a lot of neat ideas but a lot of execution errors too - but I wouldn't worry, since the latter is a LOT easier to fix than having nothing to write about.

Song and Applejack's lyrics don't sync up. This is a very big deal and should be fixed.
At first I thought would be a lot stronger without Applejack's lyrics - like, you're going for some kind of dark ambient industrial horror thing, and there's this candy sweet lyrics going on top of it? XD Then the way you use them in the ending, where you slow down and do a neat dark chord with slowed down lyrics on top is cool - but then you ruin it by mixing an entirely different bpm on top of it. But, I think the kind of mood you set with that is what you're after.
So, if you want to go in that direction, you should do some processing on the lyrics - to make them seem darker in some way. I don't have any advice for this, it depends on what you want - find a lot of tools and screw around until you and the first friend you show it to like it. After that it should be a far more coherent work, and I'll give more feedback

You should also listen to, repeatedly so you take it all in and analyze it in your head, a lot of music in the style you're trying to compose for. Industrial and dark ambient and stuff. That'll give you ideas for things to recreate, ideas for evoking moods and so on. Good stuff.