Great for One-shots and short campaigns, and while the post references FATE, it is more based around the Apocalypse Engine (Used in Apocalypse World and Dungeon World). The key is while the book has everything you need to run the game, it is advisable to pick up PDFs of the character folios. In the game you pick your characters from a stack of semi-pregens - I say semi-pregens because there are some choices you get to make as a player, but with each being unique you are assured as a player your character is special with unique talents that only have. It also makes death have less of a sting because as soon as you die you can get another player from the stack and come in as soon as possible. What I love most about tremulus though is the "choose-your-own-horror" questionaire that the group fills out and which gives the GM the seeds of the adventure.
Out of the three times I have run tremulus each story has been unique thanks to the characters and the choices the players have made.
Summary: Great for one shots. Get the Character PDFs. Tons of fun.