The Overflow Archives is definitely one of my favorite PFS Scenarios (I only have about 20 or less that I haven’t played currently, and I have GMed a few of those). I have played this once (low tier normal mode) and GMed it 4 times (once high tier normal mode, and 3 times low tier CORE). I think this scenario has a great balance of role-play encounters, environmental difficulties, combats and Puzzles.
The feel of this scenario is quite whimsical at times, and some people might not like that. Though of every table of the five I have experienced with this game has enjoyed it a great deal.
One of my favorite parts of the main Puzzle is that the part needed for success in the scenario is not too difficult and should be able to be finished even with a group that doesn’t care a great deal for such things, but there is a second part that, while not needed of scenario success, can be more satisfying for people who love puzzles.
The role-play available in this scenario is quite fun, though it is possible for a group to just hack their way through this scenario if that is their preferred play style.
The combats are interesting and varied, while fitting the theme of the scenario. I was also glad of the inclusion of a creature that I think is quite creepy and fun, and to my knowledge hasn’t been used in any previous PFS scenarios. I found that the low tier is generally quite a lot more forgiving in the combats than the high tier, but can still be challenging.
The only thing I generally did not like much about this scenario is the map of the lower level. While I greatly appreciate the theme of the map, being once a temple of Desna, it is quite difficult to draw and run combats in, especially considering the additional environmental effects happening in this scenario. When I ran this for my local group I simplified and turned the map to make it easier to draw and move around in, but I did draw out the actual map for my 3 tables at PaizoCon. I don’t feel like the change in the map had any negative effect on running the scenario.
Overall I highly recommend this scenario. I believe it would be a disservice to run this scenario without preparation, as there is quite a few moving parts, and I think it deserves to be run smoothly.