Not only was this Fonda’s first nomination, but it was his only acting nomination until On Golden Pond 40 years later.
I think the film benefits the most from Gregg Toland’s cinematography, giving the film a texture and naturalism that is integral to its theme, while still having highly stylized moments that Toland was always good at. It is “smoothed” over in a sense that some of the more graphic things in the novel have been cleaned up, but it’s still fairly authentic to the source (though I like Milestone’s Of Mice and Men from the previous year better).
All in all, though, I think it’s a good movie without being exceptional filmmaking. Well-done and professional? Sure, but I think its reputation is inflated by the fact that it’s a message movie about an “important” topic. And though the acting in general is quite good (John Carradine and John Qualen have some memorable moments in particular), I’ve always found Jane Darwell’s Oscar-winning performance to be incredibly maudlin. Judith Anderson lost to that?
Still, an important movie that everyone should see at some point.