The art is really good looking, but its not 4x4 pixels. Your main guy is, but if your backgrounds are made of 4x4s then it must be hundreds of them which sort of defeats the purpose to me.
Glad you enjoyed the art! But in fact all the mountains are made using a 4x4 tile set, the trees in the background are a layered 4x4 tile set, and the castle walls are also a tile set . The only assets in the game that do not fit on a 4x4 and are not a tile set are the player/enemy animations, the blacksmith/blacksmith's house, and the graveyards.
Here's an example of how the mountains are made: 