Confusingly, there are two kinds of "perfection". Getting the "Statue of Perfection" is just the first. In the late stages of the game, there is a whole new area in the game map that you can unlock where you can eventually track and finish achieving the final form of 100% perfection. Only then do you get "The Statue of True Perfection", and also get past the boulder.
I've done it in two play-throughs. At that point, you've pretty much beaten the game. You can keep playing, but there is not much to accomplish aside from puttering around, slaying monsters just for grins, sprucing up your farm, hoarding gold, etc.