This was a very enjoyable module. It is primarily focused on the Combat pillar of play, and the reward is also well-suited to combat-focused groups. This is probably not an ideal module for players preferring a lot of role play or exploration. However, the story makes sense, there is the chance to fight an unusual and powerful foe in an area with interesting environmental challenges, and there is some variety of enemies that present unusual combat experiences. Below I have outlined what I see as some Pros and Cons. Although there are slightly more Cons in my list, these were all pretty minor and easily workable for a DM. The Pros actually far outweigh the Cons! This is a great module!

Pros:

• great maps, easily reproducible (I enlarged them and the small area maps each fit easily onto a sheet of A3 paper while using 25mm scale)
• Definitely has the Moonshaes vibe, for players enjoying a Celtic flavour to their adventure
• Combat encounters were varied for the most part, with some less frequently found opponents making an appearance.
• Good use of interesting traps that create extra challenges within the combat encounters.
• The final fight was epic! Defeating Pryumbranth felt great for my players.

Cons:

• In some places the text did not match the maps. These were minor and most players would not notice but quick-prep DMs need to be aware of this.
• The non-combat skill checks were all far too low, so non-combat builds did not really have a meaningful place to shine.
• The big enemies needed fleshing out to make them more than sacks of hp. This was particularly the case with the Fomorian Princess Goomugh and Pryumbranth. I tried to build some motivations and some dialogue for them to use with players to add tension and drama for the group's role players.
• The encounters take more than 4 hours to run. I ended up omitting the Mushroom Forest (sadly) and one of the Orc-heavy combats (there are too many of these anyway) to keep to time. I think if your party includes high damage-dealing PCs and players who know what to do on their turns to keep combat snappy, the 4 hours is possibly do-able. However, I would suggest that DMs plan in advance to manage time and choose which encounters to abridge if required.
• Princess Goomugh just "teleports away". This felt like a weird handwave. The encounter implies that the players will engage in role play with her, whereas I think most parties will do what mine did: they have been fighting her mooks and therefore want to fight her as "the boss". No stats are provided for her. A major plot point was that Fomorians will be entering the lands through the portal if the PCs don't reclaim the Moonwell in time. Therefore, I think she should have been available as an opponent or not introduced at all other than an offstage 'possible leader who might get through if we don't shut the portal in time'.

This module is a fun Combat heavy module but again there are big Problems for very weak parties. The end can be really frustrating for some players. Again the dmg output of the Dragon is too high for very weak groups after all the Battle before. The Map of Area4 in Part 1 have some logical Problems with the hidden way and big fire in a closed chamber as well as a Hook why the Fomorian should not just attack intruders right away.

Of the three modules in this series, this one squeezes in the most combats even if they are not necessarily the most challenging. It has too many for a four-hour module and has some serious editing problems. It feels like the author wrote an eight-hour module and then hastily cut it down to five hours without doing the necessary restructuring and editing.

The most confusing part is the text for Area 4. It mentions a palisade, obstacles, a ladder, and a walkway that I do not see on the map (3C). Also, the map has another feature that isn’t explained or isn’t explained well. The War Hearth has detailed text, but it is not clear how it matches up to the map. Lastly, the text for the last combat has elements that are part of a ritual that were obviously intended to be interacted with in a time sensitive fashion, but now have no clear purpose.

Still, the module does a good job using thematically appropriate monsters and has flavorful, though mechanically typical, traps. The maps are excellently drawn, even if they don't always match the text.

The two main RP encounters have potential but would require the judge to augment them and really perform to make them engaging. The last one (Part 3) is squeezed in and is particularly flat with very little material -- less than a column of text. If it wasn’t for the NPC Appendix, a judge would know almost nothing. Also, the module rather ham-handedly pushes the players to advocate the “best” option without any of the details that would be necessary to make other options even possible.