Artist Disillusionment: Catherine Disher (Mana in the second season) has made no secret of the fact that she hates the show because of irate fans who sent her derogatory and negative letters during (and after) the production of the second season. To this day, she won't talk about the show at fan conventions or participate in DVD commentaries about the show.
Script delays were a constant source of struggle throughout the first season due to the 1988 Writers' Strike. Brothers Greg and Sam Strangis (who were both producers on the show and members of the Writers' Guild and Director's Guild, respectively) often found themselves at odds over what to do, and thus the first three episodes shot after the pilot were written under pseudonyms. As a result, scripts were written and rewritten at breakneck speed — the episode "Goliath is My Name" was hastily cobbled together just so the show could stay in producton, and the writers had to rush another concept together when Paramount vetoed a script at the last minute.
Executive Meddling reared its head in season two. According to an article in TV Zone Magazine, the show's ratings were sliding and barely above that of Friday the 13th: The Series. To that end, Paramount fired Greg Strangis and hired Frank Mancuso Jr. to oversee production. Mancuso jettisoned the present-day mentality of tthe first season, changing to a near-apocalyptic ravaged landscape that was set 20 Minutes into the Future, culled several cast members and made the material muchDarker and Edgier. To say this didn't go over well with fans is an Understatement.
Several key production changes meant there was little-to-no sense of continuity through the episodes. Executive script consultant Jeremy Hole only oversaw five episodes before being hospitalized and never coming back. Story editor Jim Trombetta left his post two months after being hired. It got so bad that Jared Martin and Adrian Paul acted as de facto story editors for a stretch of episodes.
Mancuso Jr. was reportedly angered that the show wasn't changing fast enough (even beyond its shift between seasons). Although the ratings did eventually stop their slide, it came at a very late point and funders pulled their backing. Though the show was cancelled soon after this, it did come early enough that (unusually for any television show) the creators had time to wrap up several story arcs and have a proper ending.
Even the fallout from the show stained several of its actors for many years. Catherine Disher (who played Mana) still refuses to attend fan conventions or speak about her time working on the show, as she received angry and threatening letters from irate fans during production.
You Look Familiar: Denis Forest played Marcus Cole (a renegade militant) in a first-season episode. He was then cast as the Big Bad, Malzor, in the second season. Even more bizarrely, in the second-season premiere, Colonel Ironhorse doesn't comment on how Malzor looks exactly like the individual who once took him hostage and then let him go several months (or years) earlier.
The 2005 film:
Unintentional Period Piece: This Post-9/11 Terrorism Movie isn't explicitly about terrorism. The aliens in Steven Spielberg's version of the story are very obviously meant to be a metaphor for 9/11 and America's feelings of helplessness and insecurity after the attack, and the film employs heavy use of imagery from the disaster to drive that point home.