These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Ho Yay: In the 1930 movie, in the scene where Paul is comforting Kemmerich after Kemmerich loses his leg, is very heartwarming, and also very shippy.
Narm: In the 1979 film, the scene in which Paul catches a random soldier from the other side and stabs him...and proceeds to watch him for ten straight minutes (in real time) while the man just lays there dying with a goofy expression on his face. Possibly a commentary on how it was a fellow human being that is being killed for a pointless war, but still absurdly executed nonetheless.
Nightmare Fuel: The horrors of the war are depicted in a brutally realistic fashion. The fact that this stuff actually happened should be enough to terrify anyone.
There's a brief scene where a hospitalized soldier attempts suicide by shoving a fork into his chest, around where his heart is. Since he hasn't got enough strength to drive it deep enough, he proceeds to take a boot and use it as an impromptu hammer. Fortunately, he is restrained before he can damage himself too badly.
Seinfeld Is Unfunny: The themes can look dated, because many other war novels and films repeated them.