Probably should have included a boss fight in the latest WTF is footage, unfortunately there is no direct way in the game to go back to a previous boss and fight it without having to dredge through 25+ mins of those waves prior to doing so, unless you had the foresight to manually save right as the boss began. There is a link to footage of the second boss in the description so you can watch it there, my opinion on the boss fights was made clear during the video.