FIST Tactics is an extremely ambitious FIST hack that converts the whole engine into a tactical wargame.
Seriously. Everything from height to sightlines is accounted for without compromising the breeziness of FIST's normal gameplay.
If you like highly polished projects, occult milsci, and stealth-based skirmish games, this should absolutely be on your radar.
The PDF is 38 pages, with custom artwork, a rad cover, maps, and dense but readable text.
Writing-wise, Tactics is very approachable. It's plain-spoken and enthusiastic.
Mechanics-wise, Tactics' biggest change to the FIST formula (apart from switching the game to a combat grid, adding sight ranges, adding new items, and adding substats that control different types of attack ranges) is that you play as squads, not single agents. The squads consist of individual agents, created conventionally, but playing this way allows solo players to quickly set up strategies that would require lots of multiplayer coordination and planning in base FIST.
As a skirmish wargame, Tactics also offers pvp---although pve is just as thoroughly supported.
For players, plenty of support is provided by the book. There are sample maps, guidance on the new rules, and baked-in behaviors for enemies. GMs aren't required---although I don't think it would be hard to include one.
Overall, even just to add some spice to a single FIST mission, this module is worth picking up. However it shines as a standalone game, and could be a great way to broaden your FIST game into something closer to X-Com. You might use regular FIST rules on critical missions, but Tactics rules for side ops. Or you could try a hybrid approach, using Tactics for engagements where you're commanding a force and regular FIST for engagements where you're solo.
The point being, if you like FIST, I think you should get this. It's a great alteration of the core rules and a solid skirmish game in its own right.
Minor Issues:
-Page 9, "Finishing Your Operative" Finishing Your Operatives? Squad? 'Operative' singular doesn't feel quite right for squad creation.