Concept: “Inextricable wall of bloody brambles”
Content: A vicious hazard bearing some tasty berries for the brave, foolhardy, or hungry
Writing: Straightforward descriptions of the mechanics for entanglement and escape
Art/design: Colors help differentiate text components and differentiate components of the illustration
Usability: Difficulty and damage intensify as PCs struggle; requires a bit of tracking on the GM’s part 

Concept: “In this volume you will find the most noteworthy, dangerous and strange encounters of my recent voyages.”
Content: A variety of NPCs, monsters, and other hazards as well as a new scroll, a malevolent mushroom, an optional Misery-related madness, a relatively benign tavern, and a much less benign inn
Writing: The first-person POV and travelogue style have a folksy and often irreverent tone
Art/design: Typefaces, engravings, and paintings reinforce the concept while other graphic elements lend some insidious and esoteric atmosphere
Usability: Includes player-facing handouts that include lore but no mechanics or GM-specific information

Concept: “27 pieces exhumed from the depths of lavish graves, themed around skeletons, bones and skulls.”
Content: “Classes, items, companions, monsters and encounters created by sacrilegious mind.”
Writing: A variety of styles, all appropriate to their content
Art/design: Worth downloading just to check out the range of art and layouts
Usability: Complexity varies by entry but consistently easy to use

Concept: “The hypnotic singing will lure creatures in close so the tree can ensnare them with its roots and drag them under.”
Content: A malicious tree grown from corpses; includes stats, effects of eating fruit, and a background narrative
Writing: Well written on all accounts, particularly the in-character anecdote
Art/design: Colors and images provide atmosphere and character
Usability: Don’t forget the fruit’s secret side-effect