I love the bass (square wave?) used for the synth. The sample is simple and some might say cheap, but it is used BRILLIANTLY here. Great writing on the bass line.
I'd do something more with that lavos scream; it's sort of cheesy. I'd be curious to hear how it might sound with a bit of distortion.
I love all the synths in this. They're all, like the bass, simple and not high-end, but brilliantly used.
Production is nice; each element is clearly audible, and despite having a lot going on, it doesn't get muddy, and nothing gets lost in the mix.