The people and animals on Mars are physical enough, living mostly underground and coming out for a half hour or so of sun and vitamin D around noon. Simplest case is a google search on "squirrel on mars", little ground squirrel lying there sunning himself...
it can be notoriously problematic to use 2D images to prove such things as this, since 2D images often appear to show something that simply doesn't exist when viewed 3 dimensionally. I agree that some of the images from mars do appear to show interesting forms, but I do not personally accept them as proof of anything other than that it would be good to have independent exploration of mars.
A government which keeps big secrets invites conspiracy theories...
certainly, yes - and rightly so.