Mach's tagline is "A role playing game of soldiers of fortune in a New World." It's a self-contained sci-fi RPG with a unique premise: Aliens called the Abla come to Earth in the late 20th century, inform humanity of an impending catastrophe, and transport the entire human race to the colony world of Mach.
The box set contains three black-and-white 32-page booklets. Books I and II (they are otherwise untitled) contain the rules for the game; there's no clear reason as to why some rules are in one book as opposed to the other. The third, III, is an adventure entitled "Frontier Series #1: Guilden's Farm."
Mach uses traditional polyhedral dice, mainly percentile, and has a "sandbox" feel to it. The group is encouraged to decide what their version of Mach is like, develop the starting region, etc.