The recently discovered version of Brickcraft is not the only one ever created. There is another version in particular known to exist: screenshots released in 2020 along with the announcement of the game's former existence show a slightly different game without render fog or the culling of distant studs, with debug info at the top of the screen and fewer bricks initially in the player's inventory, with the 1x2 slope absent entirely, probably indicating this is an older version. These screenshots had to have been taken in the game at some point by someone, but who, and when?
The images of this version:
https://minecraft.wiki/w/File:Brickcraft_1.png
https://minecraft.wiki/w/File:Brickcraft_2.png