In all honesty, your purchasing intent should depend on one factor only: how much do you like Green Day?
As a reviewer, it doesn't really get easier than this. Green Day: Rock Band is a package so firmly routed in subjectivity, that it's impossible for us to educate you as to whether this game is good or not. Frankly, it depends. If you like Green Day, you'll love this. If you don't like Green Day, you'll hate this. In essence, that's all there is to it.
In terms of structure, Green Day: Rock Band mimics the blueprints set by The Beatles: Rock Band pretty closely. Green Day: Rock Band does not feel as important as The Beatles, natural the material it's based upon is not important in the same way as The Beatles. Even Billie-Joe Armstrong would agree with that. That's not to say the package isn't just as lovingly crafted however.
In the career mode, you'll play the set-list of three of Green Day's most important venues — from the early days of Dookie, to the super-stardom years of American Idiot. It's an interesting span of the Day's career, which captures the band's growth from simple high-school pop-punksters to true rock legends. The background animations are perfectly fitting, from the pyrotechnics of the American Idiot arena-tour, to the scruffy looking warehouse venues of the Dookie days. It's a homage to all that is Green Day, and it's solidly put together. Again, if you're a Green Day fan, you'll thoroughly appreciate it.
As a neat little extra, performing well in songs will unlock a menagerie of audio, video and photographic goodies that'll have fans beaming from ear-to-ear. From photographs of the band when they were still in high-school (!!!), to early archive footage from MTV, it's a complete package. It features all the songs you'd want too, with the entirety of Dookie and American Idiot included, alongside key cuts from middle records such as Warning.
As a video game though, Green Day: Rock Band is nothing new. The gameplay remains unchanged, with guitar, bass, drum and three-part vocal harmony options all playable. It's standard-fare stuff.
Having not listened to Green Day for a long-time, we found Green Day: Rock Band a nice refresher in the pop-punk superstars back-catalogue. You know, Green Day are a good band, and this package reflects that. There's a lot to it, and hardcore fans will have a lot of fun with the bonus content and songs on offer. But like we said at the top, your enjoyment will very much depend on how much you like Green Day.