00:02:303 - optional but how about removing the 1/4 in the intro section (00:01:420 - 00:12:714) to have more contrast with the next section at 00:12:714? similar to #4762488
This section and the next contrast by inverting the color of the pattern. I also think the current density provides a good difficulty spread. (F -> 1/1 + 1/2 pattern, M -> simple 1/2 + 1/4 pattern, O -> complex 1/2 + 1/4 pattern)