It is a long, long time ago since I studied German, nor have I had the opportunity of speaking the language...but I found the book not downright easy, but not difficult either. The parallel definition is good.
I am refreshing German mainly as a challenge - using it just like a crossword to stimulate my brain. I am treating the text as I was taught - studying the German concentrating on it , memorizing it as best I can then turning to the English and translating that. It does the trick. If I have a word I just can`t make head nor tail of, I look it up in a dictionary rather than look at the text. That way the word is explained in full.
I don`t think it is too difficult for students - I did Buddenbrooks (Thomas Mann) this way - I first read the book in German when I was a student - years later I did it by parallel.. - I couldn`t put it down. Maybe it is better to read something like it, something you like -
If this book is too challenging, don`t give up