I saw this movie in 1993 or 1994 on TV. It was color. The action took place on a distant barren planet, probably Mars??? There it was a military/research base with a laboratory. Then these monsters which took the form of big balls and they were turning towards that base. They took the form of big balls only when they were moving. The monsters were monitorized through radars and often was starting the countdown: "They are approaching: 12 metres...7 meters...3 metres...". Once when they penetrated the base they killed a big part of the crew. Inside the base there were soldiers, and scientists in that lab. I remember a scene in an elevator, when a monster killed somebody (a soldier or a scientist). It isn't "Critters" or a sequel of this movie, neither "Screamers" (1995).

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