I became interested in seeing this film after I heard that its story was told entirely without dialogue, and that it was made in Hungary, a country which has a long history of producing high-quality animated features. However, if you're expecting Egon & Donci to compare favorably with the likes of Vuk, Son of the White Mare, or Cat City, you're likely to be disappointed.
Although the lack of dialogue makes the film unique, it is also the film's biggest problem. This is because, in place of spoken words, the characters spew out a multitude of non-verbal noises, and they do it constantly. There is scarcely a moment where the characters aren't hemming, hawing, oohing, ahhing, gasping, squeaking, mumbling, chuckling, grunting, gurgling, or making other unnecessary, unintelligible noises. This gets irritating VERY fast.
The story, such as there is, involves the titular Egon and Donci finding a crashed spacecraft in their backyard and building their own rocket so they can visit the planet it came from. Even with the film's slight running time of seventy-five minutes, it feels like it takes forever for them to get there, and after the confusing beginning, we are treated to seemingly endless scenes of the two characters having minor misadventures in their spaceship and engaging in unfunny slapstick. In the end, the discovery the main characters make on the new planet is so underwhelming, and the ending is so vague, that I was left completely unaware of what the film's point was supposed to be.
That being said, it's obvious that a great deal of work went into the design of the film, and most of the environments are beautifully rendered, with fantastic color. In addition, some of the music is moderately catchy, and the film's best moments come when the characters stop babbling and the music and visuals take over.
Overall, however, I think the one word that can sum up the experience of watching this film is "tedious." The gibberish dialogue is annoying, the story is barely understandable, the characters have no memorable qualities, the humor is completely flat, and the film as a whole is curiously lacking in the charm that is so abundant in Hungary's earlier animated productions. If you like obscure animated films, my suggestion would be to sit back and enjoy some of the brilliant films that the Panonia studio produced in the 1980s, and skip this.