Download of Sir Bombalot 1.2 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This software for Mac OS X is a product of Earth Gaming. We recommend checking the downloaded files with any free antivirus.
From the developer:
Sir Bombalot is a variant of chess with pieces offering a myriad of different options at any given time. There are seven different pieces that do everything from jumping multiple pieces to freezing those of your opponent. When any of these pieces are used in combination they can drastically change the terrain of the board, altering both your and your opponent's strategy in a moment's notice.
You may want to check out more software for Mac, such as Nightmares from the Deep: The Siren's Call, Sams Interactive Reader or Screen Immediate Record, which might be similar to Sir Bombalot.