good back-story, and good acting

Yes, absolutely, there is fun to be had, as well as many, many things to go boom, all amid an atmospheric urban jungle.

This is a small, humorous movie in some ways, but it has a huge heart. What a nice experience.

The movie's not perfect, but it sticks the landing of its message. It was engaging - thrilling at times - and I personally thought it was a great time.