If your Walking Dead Premium/LE is set up so that failing Horde doesn’t end your ball in play, then upon failure you can spam any remaining walker bombs to resurrect the mode (assuming that’s enough kills for your add-a-ball).
If your Walking Dead Premium/LE is set up so that failing Horde doesn’t end your ball in play, then upon failure you can spam any remaining walker bombs to resurrect the mode (assuming that’s enough kills for your add-a-ball).