You mean It's A Wonderful World, right? Click the link, then click the top-right button (an orange-on-black city map). Once the menu switches, click the bar labeled "PV", then click the Square-Enix Party 2007 bar.
I'm pretty freakin' excited about the game. It's about two kids running around Shinjuku (there's some street crossing there that's like, the biggest in the world, which explains all the people) trying to solve this "game" within seven days. The main character finds that he can now "listen to the hearts of others" which is what he's doing in the trailer when that big blue circle radiates out of him and everything gets all shiny. During battles, the top screen plays out like a rhythm game, which, depending on how succesful you are, will govern how effective the character on that screen is in battle. The bottom screen uses the stylus to move and attack with whatever character's on there. And the music does indeed kick some serious tushie.
The characters and concept are by Nomura, the guy behind Kingdom Hearts. I really, really hope S-E localizes this thing.