how did you find out about pop'n music?

Well, I first heard of pop'n music before I entered high school, before e-amuse even existed. I went to an arcade for the first time in a while, and it was already there. It may be hard to believe in other countries, but I think arcades in Japan are places that are familiar and easy to enter. At the time, Beatmania and DDR already existed, and they had a sophisticated atmosphere, were for single player, and placed emphasis on accuracy, so you would lose points if you pressed the wrong button, and if you played it for the first time, you would not be able to clear the stage and would die instantly in a few seconds, and it was a situation where people who could clear it were amazing.

There were nine big buttons that made sounds when pressed, and they looked cute and interesting, but the high difficulty charts were not cute and were serious charts, but several people could play one chart, and even if you pressed a button in a place that was not on the chart, it would just make a sound and you would not lose points, and even though the judgment was lenient, the sound was faithful to the timing of the press, so you could tell by the sound that someone skilled was playing. Furthermore, there was a guarantee that you would not die instantly for a few games, so this game was not scary if everyone shared the buttons and played one chart together.

 Since the game is more about enjoying the sound than hitting the buttons in time with the rhythm, I guess it's probably sensitive to delays on screen...

The sound when you press the button is instantaneous, but you can delay the timing of the video and music.

More than anything, this button layout requires you to move your arm quite a bit, but the shape of the buttons also means you can slide them like you're stroking them

I think I realized that you could do a bit of performance-like play depending on how you press them. Well, I only played a little back then, but later, when I was a university student, my girlfriend and I worked part-time in the city, and there was a nearby arcade that was open late, so we often played with the 9 buttons after work, either together or by ourselves. One day, she said she really wanted to clear EX by herself, so she bought a few PS2 CS versions and an arcade controller at an auction and started playing seriously. I think it was still magnetic e-amuse cards at that time. I think there were some good scores where the phrases were neatly separated between the left and right buttons.

 If e-sports becomes a thing in the future, I think it would be good to have freestyle with two people.

Idk I just watched a few videos of it on yt