Looks familiar -- my Joust cocktail is the same way. If I would rotate it, even temporarily, it would end up needing degaussing, even after moving back. I used a corded drill waved in circular motion over the affected area when I didn't want to wait for the degaussing coil to kick in. Worked OK, although the drill has since died.
As the fates would have it, when I rearranged the games, it has ended up facing so that it had no problems at all.