Botão do mouse esquerdo da unidade
// ============== Primary Mouse Button (Left Click) ========================
// It is true aslong the user holds the left mouse button
// Like shooting with an Automatic Gun - AK 47 :P
Input.GetKey(KeyCode.Mouse0)
// It only triggers 1 time when you click
// Like shooting a semi automatic pistol - Desert Eagle ;)
Input.GetButtonDown("Fire1")
The Real One