I just spent the last few days beating Osu Tatakae Ouendan 2 and I finally did it. So much friggin frustration! Not only that around the same time I unlocked the 'hidden mode' that just makes everything that much harder. Don't think I'll be wasting my time with that one though.
As for the game itself it definitely has something for fans of the series. The songs aren't the best but the hard and very hard difficulties are challenging even if you've mastered either Elite Beat Agents or OTO 1. Maybe if I could understand it I'd check out the wireless mode.