The most jarring UI thing has to be the back and forward buttons and up/down player breadcrumbs. I don't know if it's because I'm at 4k resolution, but the four buttons and clickable areas are smaller than my front teeth. Oof
They need to be at least a little bigger and there needs to be more space between them so you don't have to be super precise with your click.
Here is what it'd look like with the buttons 150% bigger, spaced further apart. The yellow box would be the hit area.