To make sure that all my assets maintain high fidelity when zoomed or scaled I created them at a much higher resolution then the size of the final animation. I decided to use a 4k equivalent artboard in Illustrator:
At first I thought that this would mean very large file sizes but as I'm working with un-interlaced .png files with very clean and simple artwork it presents much less of a problem. The file sizes for each element are mostly under 300kb with a few exceptions from things like complicated lighting and gradients: