I regret to say that I found this adventure very disappointing - even as a free offering.
The layout is difficult to follow. There are several boxed sections with different symbols attached, but nowhere is it explained what these symbols mean. Other AAW adventures contain the same symbols, so perhaps they have a key available somewhere as its own document, but there's no link to it. After some effort, I was able to guess the meanings, however. We have: Read aloud text (but see below), combat encounters, treasure, and some kind of broad "information for the GM".
The text - outside the boxed sections - is primarily written in third person, addressed to the GM. However, several times, it suddenly switches to addressing the players, as if it were read aloud text, despite not being in a box. To put it mildly, this is rather confusing!
Speaking of confusing, the adventure also fails to explain where a critical combat encounter comes from. The party has a dialogue with some crow-related spirits, we get some read-aloud text (properly boxed) describing a longhouse the PCs can now see, there's a nice illustration...and then suddenly a box saying "10 kobolds". No explanation of where they came from. The text just says that "The PCs should find themselves with their backs to the longhouse with a larger body of enemies pushing at them, forcing them into the longhouse for safety". Were the PCs supposed to have been running from these kobolds since the start of the adventure (the first encounter is with another, smaller, group of kobolds)? Or do they emerge from the woods after the encounter? Either makes sense, but I honestly have no idea which one the writer intended.
There are several other areas which have similar failures to explain things. Near the start of the adventure, the PCs are with the crew of a ship, seeking shelter from a storm on the eponymous island. We're told that "In the end, the captain will be sending [the PCs] off alone to venture into the woods to seek shelter". This is never elaborated on, and the PCs instead get led into the wood by a crow spirit that only they can see. I don't know if the GM is expected to improvise the scene based on that one line (in which case, I would need to understand why the captain gives them that instruction) or whether it's an editing glitch from an earlier version.
This crow spirit also has its own issues - the text just assumes that the PCs will follow it, and gives no guidance on what to do if they don't. I understand that some level of player buy-in is necessary for a published adventure, but this spirit shows up part way through the adventure, while the PCs are in the middle of helping with another situation, and after it's been repeatedly emphasised that the island they're on is haunted by dangerous crow spirits that they should be afraid of!
The treasure found in the adventure has no value listed for it. It's listed as things like "various woodcarvings", "furs and pelts" or "damaged longsword". However, this is no mere set dressing - it's explicitly offered to the PCs for helping the spirits!
The plot of the adventure is also problematic. There's an elaborate backstory, which the players never get to find out. Then the whole of the first chapter is essentially a cutscene for the GM to read out, with one place where the players are generously allowed to wander around the ship and look through a spyglass. Quick summary: PCs are on a ship, when a blizzard comes up. The captain decides to seek shelter, but the only place nearby is the eponymous Crow's Rest island, which is haunted for unknown reasons.
On landing, everyone starts unloading supplies (for some reason), and the PCs may or may not be sent off by the captain to find shelter (the text is unclear, as discussed above). They see a white crow sitting on a stack of supplies, which for some reason (never explained, even to the GM) no one except them can see. The PCs follow it, and after a brief skirmish with some kobolds, it turns into a human ghost for just long enough to ask the PCs to follow. Which they were already doing, but whatever. The crow/ghost leads them to an ancient longhouse, where we get a long infodump which still somehow only explains part of the backstory: the inhabitants of the island were attacked by kobolds and a summoned devil, and to protect their souls from that devil, the local druid did a ritual binding their souls to the land. Once the infodump is done, a larger group of kobolds show up out of nowhere, and the PCs are forced into the longhouse. Fortunately it has a protection from evil effect meaning the kobolds can't enter. They then take shelter from the storm while the kobolds place them under siege. No mention of what the rest of the crew do for shelter, since the PCs can't exactly go back for them. The longhouse is missing one of the components for the ritual, which is why the spirits are still around; they ask the PCs to retrieve it. The PCs fight off the kobolds - the spirits help by scaring the kobolds, but no mechanics are given for this. After a disappointing "puzzle" which involves doing exactly what the spirits tell them to do, they retrieve the missing item, return it, and the longhouse disappears. Finally, they have one more encounter with an ice construct made to look like the summoned devil (but which isn't that devil, just to make things more confusing), and return to the ship. End of adventure.
A skilled GM could run a good game from this, but only by using it as rough inspiration, changing the plot and inventing large amounts of content to cover the gaps in the adventure. Which rather defeats the purpose of a premade adventure. This is free, so by all means have a look at it - but don't expect to get much out of it. Not a good advert for AAW, sadly.