After playing through the game, it seems that the entire host of a chess board is an active part of trying to kill you.
You take out the Queen early, then a Knight. The entire game you're slaughtering endless pawns.
Finally, you confront and behead the King, and then the whole castle (rook) tries to kill you.
So all that leaves is the Lich, and I'm wondering why he's not a bishop?
Not really all that significant, but something I noticed nonetheless.