"Only as much fun as can be expected, when Tremors is usually more."
Tremors has, throughout its 15-year history, been about defying expectations. The first movie was surprisingly clever and witty, with nifty casting and enough genuine points where it makes the audience jump to make the leap from "guilty pleasure" to "quality monster movie".The first direct-to-video sequel retained most of the original's creative staff, which itself was unusual, and could certainly have justified a theatrical release. Tremors 3 wasn't quite so hot (though it was better than expected), but the TV series was surprisingly entertaining.
The Legend Begins is an interesting idea, transplanting the Tremors creatures back to 1889, and features the ancestors of several of the characters from the previous movies. It's also a throwback to the first movie in terms of creature design, as the villains are once again giant worms, rather than making use of the more complex life-cycle described in the rest of the series. This also lets the filmmakers revert back to primarily using practical effects as opposed to CGI, which is probably a good thing, considering the limited budget.
That's the main issue to be found with this movie - by the time you get to a third direct-to-video sequel, you're reaching a point of diminishing returns and budgeting accordingly. Gale Anne Hurd and Ron Underwood are no longer involved in the production (that Brent Maddock and S.S. Wilson, the original screenwriters, are is somewhat remarkable), and the sole remaining cast member is Michael Gross, here playing Hiram Gummer, the great-grandfather of his usual character; the rest of the cast has scant credits. That Billy Drago gets prominent "and Billy Drago as Black Hand Kelley" billing shows what kind of limitations they were working under.But, give Wilson, Maddock, Nancy Roberts and company credit - they stitch an enjoyable movie together from this. Maybe it's only as enjoyable as can be expected, but it's not bad.