I grew up in Cuba and saw Baldios (Yaltus in the Cuban version) at the movie theater when I was little. It had great impact on me. Seeing the US mutilated (and terribly dubbed) version, I'm tempted to say that this not a great movie, although it still contains enough moments of greatness, sometimes overshadowed by the occasional melodramatic qualities of the genre and the generic stiffness of the animation made for TV that was frequent in it's time period. Still I consider Baldios more than worth a look, it's more memorable and intriguing that most of the bland products made today. The faces of the protagonists are surprisingly expressive.
Baldios: The Movie was put together from episodes of an The Title Robot seems more like a strategy to keep kids interested, but the truth is that the fights are not nearly as exciting, nor the enemy monsters as interesting as his counterparts (Voltes V, Mazinger Z) And the filmmakers wisely show the robot twice (could have been removed altogther from the film)
Yet there is a reason for that: Baldios is really a gripping, tragic adult story that displays mind bending sci-fi concepts, environmental issues, and an impossible love. There is an impending sense of tragedy through the film and I can understand why many people wont like it, the ending is devastating, mostly for a kid. It was the first cartoon and possibly the only where the hope of, not just a happy ending but also a brighter future is thoroughly denied. There is no even comic relief of any kind.
Avoid the US dubbed VHS version. It's not only 20 minutes shorter, and the acting terrible, but the dialogue is also embarrassingly changed to simplify it. Some graphic moments violence have been excised as well, and important dialogue scenes have also been removed to "keep the action going" resulting in simplifying some of the characters. Try seeing the original Japanese 117 minute version. I really think that an uncut DVD version would find a small devoted audience.