The PDF you receive is missing a monster, the proper mimic, and you need to download the preview pdf to view it. The monster selection is great, and the monsters fit seamlessly in. I bought this to run a Devil-themed campaign, and the statblocks have done their job well. There is a lack of proofreading. "x" shows up in place of values more than once. For example, the Gorgon has "Init +x". It hasn't caused me any issues, but it's certainly not an oversight you'd notice with a proper Paizo Alien Archive. Lots of the monsters have full paragraphs of lore from Pathfinder alongside them to give you context. I find the little "Seargant" bits cute. It's really nice to see this alongside the statblocks, as it takes a lot more effort to give context to most of the monsters. A lot of the art is really cool, a few are a tad ugly, but that is my subjective opinion. It reminds me of a comicbook style, and is charming in that manner. The Erinyes art is weird, and some of the other art feels a bit... I don't know, man. This isn't really an issue as all of the monsters are so common there is a plethora of alternative art to pull from, but it would be nice if the book looked pretty consistently.

Overall, I highly recommend this product to anyone who GMs starfinder regularly. Who doesn't miss throwing Ropers at your poor party?