This thread reminded me of an old Outer Limitis (1964) WOLF 359 (at 12 this was disturbing)
http://www.imdb.com/title/tt0667852/plotsummary?ref_=tt_ov_pl
A scientist creates a tiny model of another solar system's planet, seeding it with life, to study planetary development. The miniaturization allows the simulation's evolution to advance much faster. A ghostly bat-like creature hovers on the in-closed model watching the humans, while emitting waves of fear terrifying them. Written by David Stevens
Plot [ edit ]
Working on behalf of corporate interests, scientist Jonathan Meridith has created a miniature version of a remote planet (the titular Wolf 359) in his laboratory. Due to the miniaturization, this artificial world knows an accelerated development, thus allowing Meredith to study its evolution through an electronic microscope, and observing the birth of archaic lifeforms at its surface. However, soon, a mysterious lifeform evolves along with the developing experiment, being apparently aware of the scientist's presence outside of the microcosm, and even acting aggressively towards him at some point. Manifesting by night in the absence of light, the creature takes a physical shape into the laboratory itself, destroying all life inside it, including plants, a colony of ants and a couple of guinea pigs. Becoming aware of the situation, Meridith weighs the value of his experiment versus the possible dangers, and resorts to firing his lab assistant and sending his wife back home, in order to keep them away from harm. Pursuing his studies, the scientist soon discovers the creature inhabiting the planet seems to be a manifestation of the planet itself, similar to its collective mind, and bent on destruction. As the evolution of the miniature world progresses, Meredith observes a reproduction of the darkest moments of Earth's history at its surface (including the development of nuclear weapons). Lowering his guard one night, the scientist is suddenly attacked by the creature; he is however saved by his wife, who returned from home at the same moment, and who breaks the miniature planet's containment cell, causing its atmosphere to escape, and subsequently causing the creature to be destroyed along with the planet. In the epilogue, Meredith can be seen recording his final report on Wolf 359, telling that the experiment is over and the planet destroyed, yet also mentioning that the experience could be a success in the future, if only one could find a better planet.