For starters, it has an unusual setting (snow-drenched hills of Korea during the initial American offensive of the Korean War) and a decent story (a black sergeant is promoted to be in charge of a platoon to the chagrin of his troops).
It's also got Sidney Poitier in the lead as (surprise) the black sergeant; he plays the role with his customary authority and dignity - although he threatens to shoot his men a lot! Ladd's role is undeveloped - apparently it was boosted into a co-star role and you can tell. He plays a sort-of racist, not convinced that Poitier should take over but not as evil as Paul Richards. Ladd looks puffy but he doesn't drag the film down. And he gets his leg amputated after having it run over by a tank - full on!
There's some authentic looking combat footage and an awful lot of talk. The structure is talk-talk-bang-bang-talk-talk. There's a real odd ball cast, most of whom who get a chance to chat and do schtick: there's James Darren, who sings a song; Ingemar Johansson, the boxer, who talks about a farm; comic Mort Sahl (very believable as a GI) who does comic routines. It's easy to make fun of some of the liberalism here eg Poitier giving a blood transfusion to Ladd - but it was pretty gutsy at the time.