Very cool idea! With some great art to go along with it!
I think that the tile moving is almost too flexible, to where you can edit a level a lot. I had some levels where I was able to avoid the (probably) intended solution, and could just make a simple line path to the chest. Although, this is a pretty unique thing to have, as not many puzzle games let you be this controlling of a level.
I think having it be a more grid locked system, where everything within a grid moves as a whole, would let you get more interesting levels, since you can have more intended solutions.
Overall, a nice game!