Steinbeck isn't exactly trying to make this hard for us. With some exceptions (and they're kind of big exceptions—we'll get there in a sec), Steinbeck uses pretty simple language to tell us a pretty simple story about a bunch of guys trying to throw a party.
So, what about those exceptions? At a couple of points, Steinbeck kind of loses it and starts comparing the characters to planets all while getting a little heavy with the biblical references (we're looking at you, Chapter 2).
But think about it this way: Cannery Row is a story about how every person is a little bit divine and how the real saints out there might be the bums lazing around outside the grocery store. Without the planetary comparisons, you've just got the story of some guys collecting frogs to throw a shindig.