"Art is never finished, only abandoned" - Leonardo da Vinci

Now while that's out of the way
To finish something, make sure you know what you want to achieve. In this case, an island made out of isometric cubes. Nice, but.. what do you want to show us?

First think or something, then create it. It just seems to me you wanted to pixel something but weren't sure what to pixel and just placed pixels along the way. And when you ran out of ideas.. you ended up with something like this.