Does this only work for R4 cards and/or emulators or something? I followed all the steps on http://altwfc.net/ and tried multiple times to get the Mystery Gifts in SoulSilver (an actual retail version) but it didn't work.
@Xdqwerty, Osu! Tatakae! Ouendan! is the Japanese version of the game, different settings/characters/songs but otherwise identical mechanics. I played that before I knew about Elite Beat Agents lol. Both fantastic games https://en.wikipedia.org/wiki/Osu!_Tatakae!_Ouendan