I've been asked this few times, so I'll put this down here for future reference.
Crimson Hangout, Balmuria: Urban Adventures, Balmuria 3: Planar Suikoden, Balmuria 4: Slaad Dungeons, Balmuria 5: Paragons and Balmuria 6: The Answer are all part of the same game universe. Crimson Hangout, Balmuria: Urban Adventures, Balmuria 4: Slaad Dungeons and Balmuria 5: Paragons are boards for retired games. Balmuria 3: Planar Suikoden is a finished game. Balmuria 6: The Answer is the currently active board and game. Crimson Hangout lacks complete logs, adding these logs is a low priority due to time constraints. The other games have complete and up to date logs.
Crimson Hangout, Balmuria: Urban Adventures, Balmuria 3: Planar Suikoden and Balmuria 6: The Answer can be considered the main plot games of the series. Balmuria 4: Slaad Dungeons is light, dungeon crawling fun set in the same game universe, but with little impact on the overarching plot. Balmuria 5: Paragons is a lower level game focusing on a single Prime Material plane and not directly tied to the overarching plot. Balmuria 6: The Answer combines aspects from all the other Balmuria games and can be seen as the continuation of them, particularly Crimson Hangout.
Balmuria: Rules and Setting is a compilation of years of custom material, homebrew and created material for D&D that's arose from Balmuria. It's not a game board as much as a place to organize all of it and clean it up.