First I have to say, that I'm a huge fan of Dorothy's books. They are all well written and the language is just perfect. I love her twisted stories that are full of surprises.
I read the "Ice Cream Girls" two years ago, so I couldn't remember all the details when I watched the series. I didn't mind the change at the end about the real murderer. On TV people want to see a happy ending and in the book you had some unfinished issues at the end, so I can see the need for a more conclusive ending.
I really can't say too much about the acting as I'm from Germany and not a native speaker. So I'm happy if the actors don't overact it.
All in all, it was a good adaption. I was happy to see, that a book I really enjoyed reading, made it on TV. If you enjoyed watching it, maybe you can start reading Dorothy's other books. They are all really great.