Osu! Tatakae! Ouendan is a rhythm game developed by INiS and published by Nintendo in Japan. It has not been released outside of the country, but has become a popular title for import. Ouendan is the first in a series of DS rhythm games, followed by Elite Beat Agents and Moero! Nekketsu Rhythm Damashii Osu! Tatakae! Ouendan 2.
Each mission in the game revolves around a character in need of help to complete a certain task. Unable to complete said task, the character calls for the aid of the Ouendan, a group of male cheerleaders who cheer the character on, motivating them to do something like clean up their restaurant to attract customers or get all the office work done in order to ask their boss out to dance. Some of the situations are actually quite dire, as eventually the Ouendan must save the entire Earth from obliteration.
The game uses the Nintendo DS's touch screen to display numbered beats. The player must tap these beats with the stylus in order and in rhythm to the song. Some beat markers are special in that they require the player to trace along a path. Other markers have the player rapidly rotate a spinner in order to fill an on-screen bar or else lose a large portion of their own life bar.
A life bar is displayed at the top of the bottom screen and slowly depletes over time. The bar is refilled whenever the player hits a beat marker, and the amount that is refilled depends on the player's timing. Missing beats will also cause the meter to drop faster.
The top screen displays a manga-style comic that details the current situation. Each song has multiple parts, and the outcome of the story depends on whether the player is successful at each part or not.
The game has four difficulty modes that change how fast the life bar depletes, how many beat markers appear during the stage, the speed in which they appear, and the leader of the Ouendan. On the hardest difficulty setting, the male Ouendan members are replaced with a female cheer squad.
- Kigaru ni Ouen (Easy): Hajime Tanaka
- Kakan ni Ouen (Normal): Ryuuta Ippongi
- Gekiretsu ni Ouen (Hard): Kai Doumeki
- Karei ni Ouen (Insane): Sayaka Amemiya
Initially, only Easy and Normal are available for play. Hard is unlocked by completing the game on Normal difficulty, and Insane is unlocked by completing Hard.
All songs are covers of popular J-pop tunes, with the exception of 175R's "Melody," which uses the original recording. The track list represents close to thirty years of music, from Linda Yamamoto's 1973 hit "Neraiuchi" to L'Arc-en-Ciel's 2004 single "Ready Steady Go".
- Asian Kung-Fu Generation – "Loop & Loop" (by Kyōya Asada)
- Morning Musume – "Koi no Dance Site" (by Kaoru Kubota, Fumio Kobayashi, Yūko Yajima, Mari Nabatame, and Akina Okabayashi)
- Ulfuls – "Guts da ze!!" (by Hiroaki Takeuchi)
- 175R – "Melody"
- The Blue Hearts – "Linda Linda" (by Daisaku Shimada of Bevenuts)
- nobodyknows – "Kokoro Odoru" (by Bugashman, Cantaman, Moss, Mouse-P, and Sausen)
- B'z – "Atsuki Kodō no Hate" (by Tetsushi Kimura)
- Tomoyasu Hotei – "Thrill" (by Hiroaki Takeuchi)
- Road of Major – "Taisetsu na Mono" (by NoB)
- Linda Yamamoto – "Neraiuchi" (by Kaoru Kubota)
- Kishidan – "One Night Carnival" (by Kei Imai of South 2 Camp)
- Hitomi Yaida – "Over The Distance" (by Ayako Kawajima)
- The Yellow Monkey – "Taiyō ga Moete iru" (by Mitsuru Yanagisako)
- Orange Range – "Shanghai Honey" (by Bugashman, Cantaman, Moss, Mouse-P, Sausen, mimi, and Akasanajar)
- L'Arc-en-Ciel – "Ready Steady Go" (by Tetsushi Kimura)