The setting and it's write-up is really nice and tight, and the system tweak looks good. The adventure structure also seems excellent and nicely adaptable. We're creating characters now with my kids and their friends and are eager to play!
Only thing that seems a bit clumsy at this time is the stunt creation system. Different stunt types easily have some overlap and were a bit hard for the kids to grasp and describe.
For me, pay-what-you-like model suits this kinds of adventures perfectly. And oh, I love the character sheet!