Each Toys For the Sandbox entry is generic , as in "stat free" (but the OSR "feel" is very much there). It also means level free, so you can adjust these for the level you need at the moment. You get a short back story, a map for the encounter area, 6 hooks to choose from and each hook has 3 twists, giving 18 variations on how you can decide to have the encounter pan out. You also get a handful of PCs (usually 4) and some appropriate random tables (in the Cursed Catacombs we get a Rumor Table and an Encounter table)
The Cursed Catacombs is a follow up, an essentially a second part, to #4, Hermit's Island. Yes, you could run them independently, but run together it becomes a really nice micro setting.
With The Cursed Catacombs, page count goes from 4 to 7 pages. The format itself doesn't change, but the extra pages allow Occult Moon to be a bit more verbose with their descriptions. It also makes the pages less
From the blurb:
In a special supersized issue of Toys from the Sandbox we return to the Hermit’s Island. Below the ruins of the old monastery are the old catacombs that once served as a reliquary and burial chamber for the monks who made their home on the island. Now filled and consumed with a dark energy these caverns have many secrets, some of which may soon reach the mainland.
Come along with us and explore them in Toys for the Sandbox #6: The Cursed Catacombs