The original Tremors was a classic and a well put together big budget Sci Fi movie. The follow ups have all been more low budget and released only on video, but have actually been OK. I mean, you can't possibly take them seriously, but they're a lot of fun and the characters wind up being pretty memorable. Tremors 4 manages to continue the follow ups while maintaining originality. This alone is an accomplishment, since many sequels end up being repetitive and boorish. Tremors 4 doesn't have this problem.
Instead, Tremors 4 is a prequel set in 1889. Perfection is a new town called Rejection and is populated by miners....until they start getting eaten. Most of the remaining townsfolk leave. The only ones that stay behind are an Indian, the Chang family, a Mexican guy, and an unmarried red headed woman. Sound familiar? The townsfolk send for a man to asses the mine, which turns out to be Burt Gummer's great-great granddad: Hiram Gummer. Hiram is a proper eastern dude who has never touched a gun and is completely unprepared. He doesn't want any business with the "dirt dragons". However, he gets swept up with the situation and decides to stay and fight the worms. He enlists the help of a famous gunslinger and together the motley crew of 8 battle the monsters. A big subplot in the movie involves the revelation of how the Gummer family became obsessed with guns, bombs, and preperation. Although, like all Tremors movies, its inherently a little bit silly and hard to take seriously, the movie is laced with nostalgic humor and for a #4 continuation, it's pretty well done and should satisfy most any fan.