I had no idea this film dated from 1961 as I watched it, mesmerized, last night. It is so well produced, written and acted that I thought it must have been one of the recent German films about WWII, like Der Untergang and Stalingrad and Das Boot. I believed the black and white film -- virtually perfect in the DVD transfer I saw -- was there only for the verisimilitude it offered.
The acting is convincing. The music is disturbing -- modern, yet "classical" to the point of being ageless.
One very minor quibble: In the version I saw, a line about the arms the soldiers will carry on their mission is badly translated/subtitled. It comes out something like "8mm pistols and .98 calibre rifles." The ".98 calibre rifles" should have been the Gewehr 98K ("K" for Karbiner, or carbine). Like I said -- minor!
One caveat: as it was produced for the East German market -- in the year before the Berlin wall went up -- there may be Soviet influences on the film that I didn't pick up on -- believing as I did that this was a post-Cold War film. If the same film were to be made today, in a reunified Germany, there might be thematic differences, but I think they'd be rather minor.
Highly recommended as both a history lesson and as a film.