Game description from the publisher:
Created by a backgammon champion, Mindgammon captures the essence of the original "backgammon", but it's different.
Game description by a BG Geek:
Mindgammon is most closely related to the Backgammon variant Acey-Duecy, where all 15 men start off the board and must be entered into the first 6 points (playing spaces) before the game can progress further. Also a roll of 1-2, once played, is followed by a second move for that player. Mindgammon has also taken elements of Old English Backgammon in that you are limited to 6 men per point.
The classic board is now laid out in a single column, making the game visually easier for beginners. Bearing-off is by exact count only. Also there are penalties for "unsportsmanlike" rolling of the dice, either out-of-turn or out-of-bounds.