As for longevity, the game consists of fifteen missions - the first of which took us about an hour or so to beat - and on top of this there's also the inevitable collect 'em up Lego games invariably become when you want to get a 100% save file.
While the numbers may change by the time it hits the shops, the preview build we played suggested that a 100% file would involve putting together all 65 Super Builds, earning 450 Gold Bricks, collecting 40 Red bricks, unlocking 110 Vehicles and finding 290 characters. The more things change (there's no co-op for example), the more they stay the same.