Just fantastic. I was introduce to Greg's work as a PC in his The Forbidden Caverns of Archaia campaign run by a seasoned old-school DM at a local game store in Houston, Texas. After a single four-hour session (which ended with half the party dying,) I was hooked. I've since enjoyed the thrill of high-stakes D&D and wanting to DM something similar to it myself (without spoiling Archaia for me as a PC,) I was recommended this product: Barrowmaze.
I've run several sessions (one reaching over 7 hours long) and the players love plundering mounds, trying to survive in the trap-ridden Barrowmaze while making it back to the village of Helix with lore to share with the local Wizard, and exploring the larger region which is rich with gameplay opportunities. PCs can easily spend all the time they want exploring the region with interesting sites and events, without ever touching (what I think is the real meat of the game) the Barrowmaze.
I'm very impressed with the large amount of content presented in ~250 pages and love how Barrowmaze facilitates player-choice with an open-world environment. PCs do not feel railroaded or uninterested in a forced plotline, because they choose what they want to engage with and uncover both the story/history of the region - and - make up their own story as they go.
10/10 for content.
7/10 for hardcover book quality (I understand the publisher is separate from the Author)
5/5 Stars :)