I love the implication that different worlds have different rules (both fictional/worldbuilding and game-procedural).
The three 1d6 tables of portal appearances, destinations and inhabitants are well-written, enough for a starter session.
The GMing advice is similar to WSCAOS, but rewritten and expanded upon. My favourite line is "If there’s a rule you don’t like, burn it as part of a ritual to
open a portal to a new world.
The little page-flip dice down the bottom are great.
Overall, a really lovely standalone game. Definitely worth the asking price.