Harmonix set out to make a Rock Band game featuring nothing but Beatles songs and visuals to match. It succeeds on all those fronts AND is really fun, so they basically perfected their vision in making this game. The only caveat is it could have borrowed from Guitar Hero's band-specific game formula by lifting tracks from similar artists, because although the songs in this game are good, none of them really push the boundaries of difficulty in a challenging way. But yeah, this is an all-time classic