I felt like all the characters were really well developed and I especially love Melanie as the narrator. She was just so real that you can't help but feel for her as she struggles with her own existence.
The ending reminded me a little of I am Legend (the book), however I much prefer this ending to I am Legend. It just felt right... or maybe it just felt right because of the compelling way the story is written? All I know is I didn't want to put the book down, and I'll definitely re-read it soon!