Have just ended running Pale Mountain for my group (although we didn't have time to actually play out the final encounter).
The "hex crawl" and expansion of the map were interesting mechanics, although the players did seem a bit frustrated by the repeated hard checks to search hexes quickly (we used the updated DCs) and the fact that they did not know where their eventual goal was. Their encounters went as follows:
First: Moving up river into the forest, they encountered the Lake Monster when it ate the Sorcerer's familiar while it was flying over the lake. This was probably the most functional fight of all, although I did mess it up a bit with a rules confusion on the Freedom of Movement spell: since the phrase "entangle or hamper you" isn't capitalized, the players argued that it did not refer to the Hampered state but to the English verb to hamper which would apply to Grabbed too, which meant that the Sea Serpent was not getting to grab on bites. It still did eat one party member and was a fairly difficult and engaging encounter.
Second, Searching the forest they met the Dryad. They did not attack, and while Diplomacy didn't go that well, they did ask if she needed any help and so she pointed them to the cyclopses (cyclopi?)
The PCs headed southeast to deal with the cyclopses and here we ran into the major problem with combat in this adventure. Fireball. Fireball has a range of 500 feet. So all the flip mats and similar were completely useless, since the Sorcerer simply chucked a fireball at the guards from far off the map, leaving them with the choice to either spend several rounds moving towards the PCs eating fireballs as they went, or to be besieged. I eventually had them move into the hall, although I am not sure if that was a good call because even though I knew that the PCs did not have time for a siege, the cyclopses did not. The PCs pushed through, entered the hall, and slaughtered the cyclopses with a small number of them fleeing behind the PCs and leaving the area.
The PCs returned to the Dryad to tell them the cyclopses were gone (actually they bought a bunch of cyclops heads with them which was not what the Dryad was expecting but hey), and she offered to ally with them. The players at that point were starting to get a bit frustrated at having no further direction from that point, so I had the Dryad tell them about the gnomish village to the southwest, since after all the book does state that the gnomes have history with the fey.
Arriving at the gnome village the PCs were welcomed and then told about the roc situation, and they moved off to the east to find the roc nest - but still had to search squares as they were going, unaware that there was nothing present there. It was partway through this search that I told them they could now see the eclipse was halfway complete and several of the players reacted with shock to the fact that a month had passed since the start of the adventure. It really does not feel right for most of the map to be empty in this way.
The Rocs decided to launch a flyover attack on the PCs camp, but were again faced with the problem that the PCs saw them from 500' away and attacked with a fireball, leaving them with four rounds of nothing but flying towards the PCs while they prepared (although they did at least split up). Yet more fireball blasts (the Sorcerer PC took Fireball in almost all his slots on the grounds that he thought other spells were too weak!) plus a Fly spell cast on the Fighter; in spite of landing some strong hits with their claws the fight didn't go well for the rocs and the PCs returned triumphantly to the gnome village where they utterfly failed to impress anyone at the Talent show but did have their requisite 4 ally points and returned to Celeri at the camp.
There was a fair bit of confusion at this point about how Celeri and the others were going to move upriver to Mistmere if they did not actually know where Mistmere was, and some mixed messages about how precise "the head of the river" could actually be. After some discussion the PCs decided to ask Celeri to move the Order upriver and wait for them, while they broke off to the Southeast to fight the dragon in an attempt to get more Treasure Points so that the Fighter could buy two magic weapons. I am not sure if that's the intended pacing, but there seemed to be nothing preventing it.
The PCs searched the southwest area to find the dragon's cavern, finding the absolute location of Moonmere in the process, and here things got very confusing. Again, the PCs saw the fire giant guard from a long distance away, although at least this time they could not Fireball him. After some lengthy discussion about what to do, they hit on the idea of simply approaching the Giant and telling him that the Night Heralds were making plans to attack the dragon.
I wasn't at all sure what to do here. The adventure says that the dragon is not interested in talks or negotiation, but this was the giant. It notes that cyclops leader previously came up to the cave and challenged the Dragon, so presumably the giant would give them the opportunity to do that; it also suggests that the giant could be freed, suggesting that the Giant is not exactly 100% happy about working with the dragon. Furthermore, what the PCs were saying was not entirely false, since the Night Heralds were right there; the only lie they were telling was that the Night Heralds knew about the dragon's presence, and the giant would have no possible way to confirm or deny that. I eventually just figured that it didn't matter too much as this wasn't a final encounter and sure enough that night, the dragon flew off to attack the Heralds, and the party returned to kill the Giant.
The Sorcerer player then suggested they approach the hoard carefully in case the dragon had cast spells to protect it. I played along with this for the moment, thinking it was an error, but then actually confirmed in the Bestiary that this red dragon doesn't have any spells. The Sorcerer player, a regular D&D GM, was baffled by this. When I later checked, I found that even if the dragon had been a spellcaster, it would have very little ability to set up protection for its hoard. There was also some confusion over what the dragon would do to the Night Heralds, given that the Night Heralds are relatively weak on ranged weaponry, but I ruled it was driven away with spells.
At that point we had to end the game because the session had taken too long. Honestly, I was quite worn out from running and not as happy about running the next scenario as I previously had been, given that this scenario had required every fight to start with a prolonged negotiation with the players about at what point the fight would start and whether or not they could simply obliterate it with fireballs from outside the defined area.
