Great job on this. I can tell this took some great effort to make.
The only thing I feel holds this animation back is audio. It could have used some nice 8bit sound effects with the action to amplify the battle. I also find the intro to be a bit dragging with all the menu stuff. It takes a while before the viewer gets it that "hey, this animation will have both faked gameplay AND cinematics baked into it". So perhaps cutting to the chase with that would have been in the animation's favor.
Apart from that I think this is really well done and I can imagine that compositing this must have taken a lot of time!