Jonnyram already put up a thread with impressions, but I thought I should start a new one with a more exciting title to get people's attention.
I've spent about an hour with this game, and it's far and away the most fun I've had with my Nintendo DS. Anyone who likes music games like Gitaroo Man or Um Jammer Lammy owes it to themselves to check this game out. It's from Gitaroo Man staff and so far seems every bit as good--and from me, that's damn high praise.
Osu! Tatakae! Ouendan! ("Hey! Fight! Cheer Squad!") is a rhythm-action game about a cheer squad that goes around Japan helping people in need. Though they wear high school cheering uniforms (in Japan, cheerleaders wear long black trenchcoats, are usually male, and "cheer" by screaming at the top of their lungs like it's the end of the world), they don't seem to be affiliated with any particular high school. There seem to be a lot of people in trouble in Japan, so the Ouendan has their work cut out for them.
Gameplay consists of three basic moves: tap, trace, and spin. The basic "notes" you hit are on-screen circles surrounded by contracting "rings." When the ring hits the circle, you tap. Some of these circles are connected to one another, and hitting all the circles in a "phrase" results in bonus points. Sometimes, after tapping a circle, gamers will need to "trace" the circle (now a ball) through a line. This is similar to the "hold and analog stick" movements of Gitaroo Man. Finally, sometimes you have to spin a circle around really, really fast. Like most rhythm action games, from these simple beginnings come devious rhythms and patterns that must be defeated.
Music in the game is licensed J-ROCK. It's played by soundalikes, but good soundalikes; I couldn't tell the difference. The songs all have full lyrics and decent sound quality. It's not CD-quality, of course, but neither does it sound like super muffled N64 samples or lousy MIDI recreations. It's definitely the best sound and music on the DS so far.
One of the coolest features of the game is the "dynamic manga" on the top screen. As you play through the song, your performance affects the story of the person you're trying to help that's unfolding on the top screen. For example, the first stage has you helping 3rd year student trying to study for difficult entrance exams. His family won't shut up, he can't study, and he calls upon the OUENDAN!! They cheer him up with a rousing rock song and powerful routine. As you play, each member of the family arrives to do their part to help (or hinder) the son. I did pretty well, so the mother made him an energy-filled dinner, the father stayed out of his way, and the younger son helped him exercise while studying, so he could power his mind and body together. At the end of the song, the student travels to the Big Board, number in hand, to find out if he made it ... success! "Gameplay" animations are interspersed with short, fast "story" segments that unfold at a breakneck pace over just a handful of musical measures bars. The only thing I've ever seen like this before is the "video manga" in the FLCL anime. It's dynamic and hilarious, but you really need to be able to read Japanese to get the most out of it.
Basically, this game is totally awesome. It's funny, it's fun and challenging, the music is awesome, the stories are adorable in that special music game way, and the dynamic manga and overall presentation is really unique and cool. THIS IS THE BEST GAME ON THE NINTENDO DS. Hopefully it will come to America.