I had a thought (and I'm not sure why I didn't think of it before): Lego Final Fantasy. There's two ways I think they could do it:

Lego FFVII
The most popular game in the franchise. They can go through the entire FFVII arc (BCC, CC, VII, AC & DoC).

or...

Lego Dissidia
But not just the last two cycles. THE WHOLE WAR! Bring in characters from the entire franchise (not just main series), maybe a couple of Kingdom Hearts characters too.