The icons are way to big along with some of the text. The spacing, icon thickness, and general layout could also be improved.
In red, you can see all those spacing issues. The space between UI elements should be the same, or around the same, lengths. Some gaps here are small, and, some are long.
In bright blue, you see the UI Corner issues. It’s inconsistent. Mostly the example with the arrow pointing to it, but others might have the same issue too. From what I’ve learned, good UI is consistent.
In yellow, you can see the giant icons. These should be scaled down so that there is blank space around the icon. The ‘center’ of the icon should be the same, just the size should be, well, smaller. The icons could also be thicker as they are quite thin.
In pink, the text is harder to read than others. Consider a specific text size instead of auto-scaling it. It seems you have quite the amount of screen that you could still use, I’d utilize that more by making the whole menu bigger as well as the buttons.
In that beige color, there are two scrolling bars. They are two different colors, or maybe transparency. They should be the same for consistency sake.
UI is subjective, but there are some principles that are mostly good to follow like consistency, color theory, and typography. Speaking of typography, the font choice here is good I’d say, you could change it, but the issue is really the different sizes of the text.