The story of the Lego Movie is told as a story within a story. Emmet, the archetypal everyman hero is literally a randomly chosen minifigure that the child (Finn) manipulates in the overarching story that takes place within his imagination.
The events of the film are shown, at the end of the film to be set-pieces that the boy has made from Lego and is peopling from his own imagination. There's no indication that they're really moving, nor have any personal agency.
Miller: They both were there from the beginning. You know, we wanted to do a real classic hero’s journey but then turn it on its
head. Where we wanted to have a chosen one who was chosen at random
and doesn’t actually have any skills whatsoever. So we thought that
was something interesting about everyone. And we also wanted to do
this other aspect of the story, which was really intrinsic to our
original concept of the movie. And so we knew the storylines had to
talk to each other. It all had to be one and the same thematically.
And each one definitely informed the other.
Lord: I don’t think we knew how it was gonna work. I don’t think we were like “Yeah, we’re gonna figure out some way where these all
Miller: And it didn’t work for like well over a year of developing it, it just didn’t come together. And then…
Lord: There was a lot of pressure to drop the more meta story because, you know, the other story was working well. But then you
don’t really need that. We just sort of thought it was such a nice,
special thing and it seems like people are more or less, I don’t wanna
say surprised, but they’re sort of feel like in the end that’s the
thing that has to happen. And I’m glad that we persevered, finally.
Because sometimes you don’t know where else the movie could go. And
you’re hoping that it has one more move, you know?
/Film Interview: Phil Lord and Chris Miller Discuss ‘The Lego Movie’ Spoilers
Obviously it wouldn't be much of a fantasy film if Emmett wasn't just a little bit magical, but only enough to make the movie a treat for all rather than a straight-up moral play.