(Honestly my rating is more like 4.999 because I had a bit of trouble adjusting to the writing style at the beginning. But the overall quality of this book pretty much negates this small fallback, making Firecracker just 0.001 short of a full five stars.)
I was completely unprepared for this utterly unique and funny book. From the very first chapter--despite my doubts on style--I knew I that I loved Astrid. I could forgive her brutal honesty and irreverence (and snark), because despite the fact that she lives in a rocket ship and thinks she's the greatest thing to walk planet Earth, she's still incredibly human. She acts tough and independent, but you can see the loneliness she doesn't even know is there. I appreciated this more than any other aspect of the book, more than the sarcasm and plot and characters--which are all awesome and shouldn't be discredited!
Basically, if this book even mildly appeals to you, take a chance and read it. It's worth your time.