Rush-Hour

If you just watch out for the 3-note run at the very end, it's a chart optimized for training your foot speed.

최후살 겹발난사 레전드 걍

Why is the bracket spamming just non-stop?

It is indeed fast, but pretty straightforward overall. If speed is not your forte, it can be quite difficult. But hardest part is definitely the bracket jumps at the end. I could have full HP before that and get obliterated by the jumps. If the jumps are hard for you, I recommend checking the video to see which foot begins the jump part and ends with which foot. It's alternating consistently so once you got the first jump right, you can legit just let your feet do the rest intuitively.