I completly agree on what you wrote me. However, the sorting method is still not working and the display still seems flipped...

Here is the result:

If you need any details on the coordinates or the base, feel free to ask!

You said that the calculus has to correspond to my transformation. I don't know how to check that, here is the base:

this.gameBase = new Base2D(
    new Vector2D(1.0 * 64 / 2, 0.5 * 64 / 2),
    new Vector2D(-1.0 * 64 / 2, 0.5 * 64 / 2)
);