The Day Mars Invaded Earth (1962)

 

Martians replace a scientist and his family to pave way for their invasion.

Very cheaply made sci-fi thriller is not particularly exciting, but does its best with its low budget - which is not much.

Maltin*1/2: "A how-low-can-you-go budget results in a "space invasion" movie shot on one piece of property and with Earthlings and Martians played by the same few actors!"