That this movie was made is a near miracle, since it squeaked out barely 3 years after Stalin died; and the Polish film industry could even begin to suggest that Poles could struggle against the Germans without Soviet "fraternal" help. It looks likely that it was saved from oblivion by the Silver Palm (1957), at least in Poland. My suspicion that this got past the Party censors as a Dantean allegory about the worker and peasant struggles, with each character and episode exposing some lesson. However, like Ashes and Diamonds, much of the real message is just at the surface: regular Poles struggling for a better future.
The real hidden message of the film is a metaphorical struggle against Soviet oppression. Wajda seems to suggest this by quoting Szczepanski(1944): "... But know this: from our tombstones A victorious new Poland will be born And you will not walk this land You Red Ruler of bestial forces!" (1) Indeed the resolution suggests the Stalinist Inferno is far from over. Those who have tried to bring light to the world suffer a Promethean fate.
What seems remarkable to me is the positive spirit, humor, and love of life that most of the characters display in the face of their passage into the underworld. There is additional irony (humorous to me), for example, that the composer attempts to play a particularly patriotic Chopin, but is then ordered to play "something with feeling:" an inane dance tune. (By the way, the Beckstein piano that the composer tries to protect was made by a company that provided Hitler with crucial early support.)
It is also remarkable that such a dark, almost anti-heroic view of combatants was made only 12 years after the event. It is not so far from the spirit of Ernie Pyle, and just think how long it took to make Band of Brothers.
(1) Interview on www.wajda.pl