Progress bars look a bit weird. When the progress bar is half way through, the beginning of progress bar is a bit square where the not yet reached end is more rounded. This makes the progress bar look strange and inconsistent.
Also when the progress bar reaches the end, it seems like it never actually reaches it. Even if menu has to move on, let it fully render for half a second so you see it reach the end. A small cosmetical thing but would be a nice touch.