TL;DR It's beautiful, it's cheap, it's great fun. You should buy this game.
Overall the system is simple, clear and intuitive, it uses a 2d6 system to play. Players roll 2d6 + attribute for all rolls, the only exception being when a character is inflicting or recieving damage. There are 4 attributes FORCEFUL, TACTICAL, CREATIVE & REFLEXIVE, they were each well defined in the documentation and at no point in playing were myself or any of the players unsure about which attribute to use ina certain situation.
The influence of "simple world" which is listed as having helped inspired FIST is clear, but ultimately FIST does enough to make it it's own.
The documentation quickly establishes a theme and maintains it throughout. Once again some of the items listed as to have inspired FIST have a clear influence but FIST manages to blend them together with enough original material to create something that feels familiar whilst being new and exciting.
The documentation is simple and sleek, but gorgeous. It's simple black & white design and at 19 pages long the documentation is printer friendly for those who wish to print and play.
There is enough variety of character "trait" options that players can get creative with their character builds, but not so many that character generation becomes a chore. Traits typically offer a mix between powerful abilities, attribute points and weapons or items that could help the character in game. The traits seem balanced and offer surprising depth and huge variety in potential character builds.
The character "role" options helps give players direction in how their character could act without being overbearing. The fact that player advancement is tied to these roles means that players look to fulfil these roles to advance but can get creative about it.
In conclusion, it's a great game and an absolute steal. If you like metal gear solid, deus ex and the a-team, you will LOVE this.