Do you know how landforms are made? The face on Mars is a landform. Here are a couple reasons why I think the face is a landform, and not a structure made by aliens.

One reason I think the face is a landform, is because the sand on that planet builds up and increases into a mountain. There are also astroids that strike the planet, making the planet have different size shapes on its surface. Also, there are tectonic plates to move the land.

One other reason I think it is a landform is because, if aliens were to create the enourmus structure, how would they do it and why would they do it? To me, there is no other explanation other than it was created by natural landforms. Also, whos to say that aliens are real or not? It wouldnt matter because even if people said aliens are real, they would need to have evidence explaining why and how aliens accually exist. Then and only then, would I consider looking into the matter of aliens creating the structure.