Surviving The Ohey Ruin is an expansion for No Nut November: Squirrels Of The Post Apocalypse.
And if you haven't played No Nut November, that game is a joy. Silly concept, laser-precise execution. Everything that's good about Fallout or Gamma World mixed with a surprisingly interesting range of facts about squirrels to produce something unique and extremely fun. Seriously, if you like shorter, pulpier TTRPGs, look it up. You're missing out.
Getting back to Ohey Ruin, the PDF is 17 pages with stock art, new rules, and even some fiction. It's got the zine-y feel of the core book, but the writing and design are similarly very strong.
Contents-wise, Ohey Ruin is a bit like playing Fallout 4 on survival difficulty. Injuries now have tags marking what kind of source they came from. Squirrels can dehydrate, overheat, or freeze. Food can irradiate or infect. Crafting has its own subsystem. You can build settlements. Gear can be damaged and destroyed.
All of these new subsystems are interesting to interact with and add a layer to the game that encourages more long-term play. However the way the information is organized does sometimes feel a little strange, even if there's no ambiguity as to how anything works. You just sometimes have to hunt around the book to get all the context on something like a brittle crafting material.
Overall, this is a great expansion for adding depth to No Nut November. If you're planning on playing a campaign of the game, I'd strongly recommend adding it to your library.
Minor Issues:
-Page 12, Corruption, it's not explicitly clear that you roll on this table each time you take Corruption.