This is the only iteration of Tom Sawyer where Becky and Huck interact at all. They don't in Twain's books; or any of the other movies or TV shows.
People have criticized and ridiculed this series for integrating the real life drama of the Tom Sawyer franchise with Sci-fi and fantasy adventure; stating that is not what Samuel Clemens had in mind. But actually Clemens was planning to write another book in the series called "The Mysterious Stranger" which did incorporate real life and fantasy/sci-fi: "The Mysterious Stranger is a novel attempted by the American author Mark Twain (Samuel Clemens). He worked on it intermittently from 1897 through 1908. Twain wrote multiple versions of the story; each involves a supernatural character called "Satan" or "No. 44". All the versions remained unfinished (with the debatable exception of the last one, No. 44, the Mysterious Stranger)."
Critics were not at all impressed with the series. "An ideal time to turn off the set and read the stories to the little loved ones," wrote Bob Williams of The New York Post. Said Rex Polier of the Philaldephia Bulletin: "tried, but failed to achieve the wonderful whimsy of animation by Walt Disney." C.J. Skreen of the Seattle Times was more scathing, writing that "partisans of the greatest American novel are not likely to take lying down what the Hanna-Barbera cartoon factory has done to Huck Finn." The critics who wrote this review; and claimed that Hanna-Barbera was "blaspheming" Mark Twain by dragging Tom, Huck and Becky into the sword and sorcery and fantasy genres; did not realize that Twain had already done this himself. "The Mysterious Stranger" was an unfinished novel by Twain that has Tom and Huck encountering Satan himself. And "Tom Sawyer Abroad" cross-pollinated Twain with Jules Verne adventure novels. So this TV show was not that far off from what Twain (AKA Clemens) was writing in the first place.
Many future adaptations copied little things from this series. Big River; which was a big Broadway hit in 1986; and a musical adaptation of Huck Finn; has a theme song with a line in it:"Look out for me! Oh Muddy waters! Your mysteries, are deep and wide!" This line appears to be lifted from the lyrics to the theme song of this show:"That Mississippi, she is a mystery!" And overall the theme song to this show is very similar to the theme song to Big River; if you listen to them both.
Kevin Schultz who played Tom Sawyer was a twin and his brother Keith Schultz also tried out for the part. They looked so much alike that the guards at the studio just let Keith in, thinking that he was Kevin.