I'm glad you had fun and liked the music! I was using a PS1 shader so that was the main cause of a lot of the graphical issues you mention since I had it set up to use vertex jittering and affine texture warping. Plus I was using the Unity URP shader for the transparent textures which sadly doesn't render layer transparencies in the correct order.
Yeah, the zombie walk animation was a bug that I left in since I found it funny at first, but maybe I should have fixed it. Anyway, thanks for the feedback!