This is a lovely little "mash-up" of the wild west genre and sci-fi thriller, which may appeal to fans of the Cowboys and Aliens, Alien films and steampunkers.
This is a bold move by Mongoose to use their Traveller system, deviating from traditional Traveller products as it adapts the mechanics and ramps up the equipment details to root players in a Wild West setting - as opposed to just applying generic backwater world "Low Tech Level" brush.
If you're a loyal fan of the imperial galactic "feel" of the Classic Traveller canon, this might not appeal as a Traveller product per se, but if you like the Mongoose Traveller system and have a relaxed approached the gaming you will possibly enjoy the extra gloss and grit of cinematically style cowboys and their feisty female companions.
As well as adventure details (the "Town of Bent River"), a choice of alien adversaries, there's even the class / career of "Desperado" and a bunch of fully equipped pre-generated characters which actually makes this a "pick-up-and-play" supplement in my book. Even your horse can have a personality quirk - which reminds us that horses in some ways are NPCs or hirelings with relationships to the characters in their own special way. Not to mention the fact that horse-riding can be dangerous in itself - but this is optional stuff.
It's a great little supplement (50 pages), and if you don't own any games with Western/cowboy settings, there's a fair about which can be "mined" for other systems.
At $9 it's a bit pricey if you're "just curious" - Perhaps $5 to $6 would have been better for this supplement in PDF form.
If your enthused by Traveller and Cowboys and Aliens (or Alien but with a lot of dust) this is a must-buy. If you think you can do something like with you're own choice of system, there just might be the odd little detail which will improve your game.
I'm very drawn to the Giger's Alien styled "xenomorph" vs. the Magnificent Seven. ;)
Full marks for ambition and style!
(Edited from review and commentary at http://bit.ly/rpgblog )
[5 of 5 Stars!]