This is a newer book from Michael Gibbons who also does the illustrations. Here we get a full (8.5" x 11") PDF at 104 pages with Black & White art. The author makes a note that the B&W art fits the mood of the game and I can't say I disagree.

This book also is more inspired by Burroughs, but the DNA is a little more obvious here. Also, the book is designed to be used with B/X style games, this also goes to level 10 (not level 14 as some B/X games). That's also great by me.

The classes and these are race-classes, are Princess, Warrior, Thark! (no idea why the ! is there), Menton and Terran. The classes are pretty much what you think they are. A couple of points. Princess is only open to Red Martian women; there is no Prince class (and sadly no Purple Martians). The Menton is a psionic using class with powers detailed in the book.

There is also something called "Mastery" which works a little like Feats from 3/4/5e but has a solid B/X/Old-school feel to them. They work quite well here.

There is a Campaign/World-building history here. It is some good background and fun to add to any game whether you are playing as straight-up Barsoom or something else.

This book has a completely different feel than the other Mars books out there. While all the books I have looked at list mostly the same sources as inspiration, this one comes closer to Heavy Metal than most. Also if I ever wanted to play a Herculoids game this would be the first book I'd grab.

The art has a really cool style that I don't often see in modern RPG books, but it fits this one perfectly.