I say it is quite an interesting story, yet it has some sad parts in it. For example, Lennie is never aware of his own strength in both Of Mice and Men the novel, and the movie, although according to the novel, and George doesn't feel sad after shooting Lennie. The similarities in the book and its movie will reveal the differences, which we will see why there is two different works about the original story.
The similarities between these two stories are obvious as well as George ends up sitting in the train in the beginning and the end of each story. It's also similar because the way george is described is the same as the movie and book. Overall, the storyline is just about the same in both stories. The quote "Lennie didn't do nothing." is used in both versions as well. Lennie kills the little labrador puppy "Because he maked like he was gonna bite him" the same way in the book as in the movie. Something really noticeable is that Curley's wife has no name in either versions. Those are some of the similarities, but these two versions of Of Mice and Men aren't exactly the same!
There isn't as many differences as there are similarities in the stories, but they are very noticeable, for example, in the book, Lennie is described as "big" and "dark around the eyes", but in the movie Lennie isn't fat and he is white so you can see his eyes clearly. To me, he looked pretty average except you can notice there is something wrong with him by the way he acted. There are many quotes in the book that aren't said in the movie. It's good to know that both stories aren't "exactly" the same. Then, if you read or watch one, you wouldn't have to read or watch the other. Unless you are supposed to be comparing or contrasting each, that's a different story!