This adventure is 18 pages long, 1 page front cover, 1 page editorial, 1 page SRD, leaving 15 pages of content, so let's check this out, shall we?
This being an adventure-review, it contains SPOILERS. Potential players might want to jump to the conclusion.
Still here? All right. The adventure opens with the PCs getting an invitation to claim an inheritance at a farm in the idyllic town of Shadowfield. Once they have ventured into a carriage and gotten there, they'll have to contend with a rather unpleasant discovery - the originator of the letter is rather dead and musk-creeperfied and some force wants revenge - turns out, the PC's ancestors have brought a heinous serial killer to justice and now his revived form (an undead scarecrow) has prepared an extensive gauntlet of traps and assaults to settle the old score.
While the town is detailed and even all of the NPCs get their own statblocks (and background stories including adventure hooks!), the basic plot is rather obvious from the beginning, as are the myriad ways open to the PCs finding the cave system beneath the farm that hides the sanctuary of the foe. The caverns, though, are rather interesting, as the traps they contain tend to be on the smart side and all of the encounters use environments stacked against the PCs for tactical combat situations as well as mood-setting elements. The adventure has the distinct possibility of the villain being defeated prior to the final encounter, but offers advice on his rejuvenation for the showdown.
Editing and formatting are top-notch, I didn't notice any glitches. Layout adheres to a printer-friendly two-column standard. The pdf comes with extensive bookmarks and includes all stats necessary to run the adventure. Artworks are b/w and ok. We get 3 maps, 2 of which (the farm and the town) can be handed out to the players, as they contain no spoilers or annoying numbers that spell out the locations for them - excellent service and adds to the value of the pdf.
I like this adventure in that it's simple, can easily be run almost spontaneously and offers a nice first level introductory scenario. That being said, while the writing is atmospheric, I can't see the horror-aspect working well with regards to my players. Why? Because this adventure is very easy. While the traps are rather devious and not to be taken lightly, the main adversary is rather weak and the fact that a special rejuvenation beyond the first per se is not included somewhat drags down the scariness of the foe. Also, the adventure serves the background story/truth behind the assault to the PCs on a silver platter in the first encounter, essentially invalidating any need for investigation and thus depriving the adventure of the phase of rising tension. While this enables the adventure to be run very fast-paced, it also means that veteran players will not be particularly challenged by this module. I know that my players would be done with the adventure in under 4 hours. While you always can complicate the plot, as written it felt too simple for my tastes.
That being said, "Sin of the Fathers" still makes for a nice evening of roleplaying that probably won't see too many PC-deaths and a neat introduction to a new campaign, especially for less experienced players who want to delve into the horror genre without facing the often rather deadly horror-modules out there. My final verdict will take this into account and be 3.5 stars - round down if you have rather smart/experienced players and round up if you're looking for a scenario that goes easy on the PCs but still offers a creepy atmosphere.