As a long-time fan of the Parsantium setting and a 13th Age GM, this adventure has a lot going for it. First, kudos to the author for including a half page detailing the Parsantium icons that are likely to be involved with this adventure and how they'd fit in. In 13th Age, icons are impartant for both building stories and for the mechanical benefits derived from PC relationships with icons, and this goes a long way to making the adventure easier to run with 13th Age, even though the stats are for 5e.
Without wanting to spoil too much, I'll say that I enjoy the mechanic that ratchets up the tension as a result of NPC death toll rising as the party goes through the adventure. A smart group of PCs will find non-lethal solutions or they'll face a more challenging adventure. You don't often see adventures written that encourage characters not to go "murder hobo" on most of what they encounter. It was nice to have an in-story reason why the group will want to think twice about this approach.
The inclusion of ideals, bonds, and flaws for the NPCs is helpful in easily picking up this adventure and running these NPCs without needing a lot of prep. While D&D 5e isn't my game of choice, I've run and played a fair amount of it, so it's easy enough to take the monsters and find/create 13th Age interpretations. Several of the monsters can be found in the 13th Age core book or bestiary. Others (such as a couple giant animals found in the adventure) can probably be reskinned from existing giant animals in the core book.
If Parsantium is part of your campaign, this adventure will serve as a nice starting point for a new group of characters. I would have liked to see suggestions on how to use this adventure for a range of levels, rather than just 1st level. In 5e, PCs don't stay at 1st level for long -- they're typically level 2 after just a session or two. So this adventure isn't going to be challenging enough for groups that aren't just starting out. I don't hold this against the adventure: it clearly states that it's a level 1 adventure, and the challenge seems about right, but it would have been a nice-to-have.
[5 of 5 Stars!]