Good

I did really like it, but there is something wrong. It kind of feels like tension is always building, never really released. You know what might fix that: you have two iterations of the song, you go through it once and then you go through it again. Why not change the second iteration so that it has a low humming like engine in it, something that would remind listeners of the moving platform Mario rides. That low hum could create a progression, moving the song from "menacing wall of cannon" to "threat in motion." Just a thought.