The fifth and final game in the Sabreman series, Mire Mare, was planned by the developers but never released. It was intended to be Ultimate Play the Game's "swan song" before Ultimate was sold out to U.S. Gold. Unfortunately, the sell was completed faster than expected and Mire Mare was never released.

Three of the Sabreman games reference Mire Mare as part of their plots. The second game, Underwurlde, actually contains three exits for the player to finish the game. Two of these exits inform the player to continue on to Knight Lore and Pentagram, the third and fourth games in the series, respectively. The last exit tells the player to continue to Mire Mare. Additionally, both Knight Lore and Pentagram leave messages upon completion telling the player to go to Mire Mare as well.