M. Allen Hall is on Kickstarter with a game called In Ruins, which starts with building castles.
However, neither the castles nor the crowdfunding for In Ruins will be around for long, as we only have until March 25th to back the Kickstarter.

The game is for between one and six players, and it begins with the construction of a castle. That Castle falls, and what’s left is the dungeon. In Ruins is about the factions competing for control of the dungeon.
It’s part cooperative storytelling game and part network-building game. The story half comes with the Castle and ends with a battle over differently valued rooms.
The gameplay uses a deck of cards, pencils, and graph paper, although Allen recommends some d6, too. It can be played solo.
The factions of In Ruins are based on classic fantasy roleplaying characters, such as Kobolds, Slimes, and Cultists. Each faction has a unique ability that they can call upon to gain the upper hand as they spread their territory through the dungeon.

Backers at $8 get the PDF version of In Ruins. There’s an estimated release date of September 2025.
At $20, the backer reward levels up to include a physical version of In Ruins, which also comes with the PDF. Shipping is extra, but worldwide, and the release date is still September.
There’s one higher tier, $35 also adds in a 6×9″ print of the cover art and an 8.5×11″ tear-off pad of castle sheets, pencils and player reference cards.