Of the countless war movies I've seen over the years, I can honestly say that this is not one of the better ones. Sure, it has some interesting aspects and even a few suspenseful scenes, but the overall effect is not very impressive.
The thing that struck me most, and the least believable part of the whole movie, is that the same squad of the same platoon of the same company of the same division would be the first unit on the beach in every major allied action from Operation Torch to Kasserine (I know, no beach) to Sicily to Normandy and beyond. Strains credulity just a bit, in my humble opinion. A few of the other scenes were just too surreal for my tastes, for example, delivering a baby in a knocked out German tank, or clearing an exit on Omaha beach with the very first bangalore.
On the positive side, Lee Marvin and Mark Hamill do decent acting jobs, and the scene where the squad comes upon a German death camp (I think it was Auschwitz -- this squad is first on the scene at all the big stuff) is somewhat moving if overdone. I suppose it's fair to characterize this movie as an attempt to encapsulate the entire G.I. experience in WW2 in a two hour movie by showing every major battle, and it that respect I guess it has a measure of success. Still, for someone who watches these movies from the perspective of an amateur historian, I wasn't particularly impressed by this endeavor. Watch it solely for its limited entertainment value -- it's not good for much else.