This is a fully playable demo rather than the finished product, and as such is missing quite a number of things, but is more than enough to play. So be warned - the full game will have more content and this is more a very functional preview or a lite version. It's wonderfully presented (as anyone who knows any MWP games will know) and very effective.
It is also the second system for running in the Firefly universe, with the first being Margaret Weis Productions' Serenity using the Cortex system. The two systems are very similar, both light and fast flowing - and haveIMO too much volatility with the inept having decent chances to beat the experts.
Ultimately, however, the difference between the two systems is one of emphasis - Firefly ows a lot to the previous (and excellent) Leverage system for which MWP subcontracted Evil Hat (Fate Core, Spirit of the Century, Dresden Files). And whereas Serenity put its focus on questions like "You are Ianara firing a bow from behind a rock at goons hiding behind pillars. How much less damage do you do than Jayne with Vera?", Firefly puts its focus on questions like "You are Jayne and have just punched someone out for making fun of your cunnin' hat. How much trouble have you just created for the rest of the crew to deal with later?"
And that second type of question is, to me, the core of the 'Verse. Combine that with a couple of excellent and fun (if very slightly railroady) adventures (one being intrigue heavy and involving weddings and popular princesses, and the other being a romp of a race to rescue orphans) and you have an excellent game.
[4 of 5 Stars!]