This is an absolute must buy for any John Carter fans. the spirit and tone of the original books are perfectly replicated in the modified 2d20 system. the removal of skils and focus on the talets is a good choice and fits the settign well.
I probably would have given five starts, but I don't think there is enough information about the details of daily life of the base cultures, partiularly the green martians. I doubt that someone could pick this up and run a game without having read at least the first book of the series.
[4 of 5 Stars!]