The beauty of this product is in how well it dovetails with the other Dragon Warriors mini-campaigns ('Elven Crystals' & 'Sleeping Gods'), but also that it is solid enough to stand alone if required.
The sidebars throughout the first section on the city of Glissom are a great addition and highly entertaining (especially the one on games played at one of the local tavern) and have been designed to give the GM a bit of insight into how the average day in the city could be played out. There are plenty of cultural quirks to make life interesting (for example, the section on the law should give rise to all sorts of roleplaying opportunities in this city), whilst there are also lots of memorable locations. For the latter, I'd highly recommend the very short section entitled 'Into the wild.'
Next, we are treated to a range of one paragraph adventure hooks linked to the locations discussed previously. There is a good mix of ideas, but really these are only very small sparks for the imagination. In true 'hook' style, you'll need to put a lot of work in if you want to construct an adventure around them. The overall quality is good, with a mixture of seemingly mundane and overtly arcane ideas, so a GM will be able to find an idea that will appeal to their party.
The adventure provides a good mix of challenges and there are definitely some old-school flavoured encounters sprinkled throughout, such as the Inn, the Siren Wood and the City of Mimir. However, there is a clever, consistent design to most of them, which adds to the story and the goals of the NPCs. In fact, the entire section in the Woods could be lifted and placed into any campaign world for a full night of challenge - you'll never look at the terrain, or the inhabitants in the same light again.
The final encounter has a number of surreal elements which give it a strong, mythic feel. Dragon Warriors authors have always been good at this - I often feel that when one relates the tale of one's adventure, the authors have given you the tools and experiences to make your story sound like legend.
On the note of terrain, this was the only part of the book which really needed a bit more work. As the weather was described evocatively, the scenery changing to delineate each scene, and the story hinging on a great thaw - I expected there to be a bit more interplay between the environment and the party. Alas this was not so. Whilst it would have been nice, it takes little effort to include some conditional effects and challenges, so this hasn't influenced my rating too much at all.
As a mid-level adventure (5th - 7th level), the combat encounters are appropriately pitched to give the characters pause, but unless they do something incredibly stupid, I can see consistently hard challenge as opposed to a total party kill. That said, the encounters are easily scalable, and the environment and encounter terrain can always be used to give critters an advantage.
The production values are up to usual Dragon Warriors standards in that they evoke the feeling of old school RPGs in the artwork and cartography - both of which are very pleasing to the eye. The layout of the book aids its usefulness, and all the information you need for an encounter or scene is usually on the same page - a welcome change from some other fantasy RPGs. I'd recommend this adventure book to any GM of fantasy RPGs, not just Dragon Warriors.
A top-notch product, and Serpent King should be applauded for keeping this classic game in print.