FEAST is a five-in-one expansion pack for FIST.
The PDFs are well-organized trifolds with solid, zine-style art and layout. The text is slightly dense, but easy to read.
Purple Rain (the pdf is named Red Dirt) is a short and simple op about investigating a terrorist facility producing metahumans.
No Snakes Alive is a series of tactical engagements against a wide open operating theater with a kaiju at the end of it.
Pact is a collection of extraplanar entities that can be bargained with or fought.
Future Combat is a small assortment of milsci weapons.
And Mage is a new faction plus a set of new, suitably occult feeling, spellcasting rules.
Overall, everything in here is solid an enriches the core game, and you get to pick and choose what to apply. Purple Rain is a fantastic intro scenario. No Snakes Alive understands how to make a dang good Metal Gear mission. And everything else adds flavor to the base game. If you're just dipping your toes into FIST expansions, these should probably be some of the first you look at.