Yes, Pop'n Music. Think of it as Beatmania IIDX's slightly less hateful, significantly more colorful sibling, with a broader taste in music and a learning curve that assumes you haven't already been playing the game for 10 years (note: you might want to read that article I wrote about IIDX a year ago; the terminology in there gets reused a lot). There's a guy on youtube who uploads autoplay videos of easy songs, too? Well, there you go. Here's a video of one of the hardest songs in the game, just to even things out.
The big difference between Pop'n Music and IIDX is, as you've probably guessed, the method of input. IIDX is played with that bizarre turntable-piano-monster thing, while Pop'n has an array of 9 gigantic UFO-catcher giga buttons, each capable of generating a sound louder than a violently convulsing washing machine. There's no way to adjust the scroll speed of the notes on a per-pixel basis like in IIDX, and there are far more excruciating mindfuck songs with insane speed changes, so folks tend to play at even faster Hi-Speeds than in IIDX. S-Random is a lot more popular than Random for whatever reason, and it's here that you actually end up having to use your arms and elbows to hit certain crazy note combinations that only show up when everything gets thrown in the blender.
There are also ojama (literal translation: annoying bullshit) which range from scoring goals to bizarre, Mario Kart-style disruptions of gameplay where your notes fall at the wrong speed, spin violently, or become blocked out completely by god knows what. These are all optional, and can be turned on before any song at your discretion. The harder/more insane the ojama, the more "challenge points" you earn. More challenge points means a greater chance of getting the extra stage in the arcades. Really, though, most people just turn 'em on for fun.
Obviously, I could write an article about this game all day. I shouldn't, though. This is supposed to be about how Konami keeps screwing over Pop'n Music's console audience. So let's talk about that!
Exhibit A: Konami has released 17 mainline arcade installments of the game, with the most recent being Pop'n Music 17 THE MOVIE (like IIDX, the "theme" of each game has almost zero bearing on the actual music in the game, outside of one or two songs). The latest version of the game on console? Pop'n Music 14 FEVER. Initially, folks just assumed Konami was biding their time before releasing the best console port ever, but after nearly 3 years it's all but assumed that Konami's never doing another one of these games on the PS2. This was already a pretty big slap in the face to people who had shelled out crazy money for an arcade-style pop'n controller. It gets worse, though!
Exhibit B: Beat'n Groovy. Oh my god. What do I even say about this thing? It stems from the same proud tradition that brought us the North American release of beatmania and Rock Revolution. It's an Xbox Live Arcade game, which means that in addition to the embarrassing graphic design and busted play mechanics, there are also only nine songs in the game. Based on the online leaderboards, about 7,000 people bought the game. I can never figure out why Konami keeps making stuff like this, but everyone involved should probably be ashamed. Thankfully, it doesn't really get worse from here. Sorta.
Exhibit C: Pop'n Music Wii. A standalone "reboot" of the franchise which replaces the game's original extremely satisfying visceral button-smashing controls with awful wiimote gestures. It bombed in Japan. In North America, it just got a stealthy release with no fanfare. We're talkin' so stealthy that not even bemanistyle knew it was coming out. When your obsessed, hardcore target audience doesn't even know your game is out, something is wrong.
Clearly, Konami doesn't really seem to give a shit. Unfortunately, they recently announced Exhibit D, Pop'n Music Portable, in which they reveal, horrifyingly, that they kinda do. Here, at last, is the port of Pop'n Music Adventure that fans were clamoring for, but it's on the PSP. The control scheme looks unplayable: you can play Pop'n on a dualshock, sure, but that thing's got four shoulder buttons to the PSP's two. Who are they making this game for? It looks like they put some effort into it. Why not just release a PS2 version? Has that ship sailed? Gosh, it all feels so inexplicable!
In conclusion: yeah, hey, whatever you want Konami. We'll see when it comes out.