Thanks. My first thought when I saw this was "....and that's it?(!)"

Warning: This one takes about 10 seconds to render on my i3-3220. Chrome/other tabs are still usable, this one just turns white for a bit.

...And it does not scroll quickly. Haha

I'm also mildly impressed at how many rectangles I'm getting - I have the Noto font set installed...

It's true that the OP page skips a lot of characters (including all the Han Chinese characters -- it occurs to me that I have no idea if Unicode says anything about how these characters should be sorted).

But the page you're linking is different, it's just iterating over all codepoints in order by their codepoint number.