In the entire Fighting Fantasy series, this adventure is unique. First of all, you play an elf instead of a human adventurer. Secondly, you can travel in dreams as well as the "real" world. Thirdly, the scenario involves a landscape blighted by nightmarish forces, while also dotted with dreamlike elven magic sites. Expect some of the most weird and creepy images anywhere in the series.
There are at least two ways to complete the adventure. It's doable, although the final battle is tricky unless you collect 6 items along the way; one of these has a 1/2 chance of dying before you get it. This said, the adventure is very playable, with a number of different sidetracks and areas to explore. The dream aspect stops it from becoming too linear - in the later stages you can switch between dream and real planes almost at will. I found it very playable, although the final battle is a letdown (you need ALL the six items or the ones you collect become useless... they are used at once, and don't have special functions... kinda disappointing given the unusual nature of the items, and I've seen this stuff handled better elsewhere in the series).
Story-wise, it's an intriguing scenario focusing on nature and corruption, a tale which is allegorical for industrialisation, viewed from the perspective of the marginal. There's some great observations, too - a nightmare where the nature-loving elf character is transported to a modern future, written from the elf's perspective, is insightful.