The infamous Battletoads had a somewhat equally infamous bug where when you would reach the eleventh level with a friend playing alongside you his or her character would be unable to move. In order to progress that character would have to lose all of their lives, leaving Player 1 to progress alone.
Speaking at San Diego Comic Con, Craig Duncan, head of Rare, answered a fan question regarding this bug in Rare Replay saying,
We’re aware of the bug. It’s part of Battletoads legend. We have a way of fixing it, so it is something that’s on our final bug list.
He later clarified,
To answer the question directly, yes, we’re gonna fix it.