You mop if you stand still and press J, and you swing if you move and press J. I hoped that most people would be able to figure it out, but it's not as intuitive as I hoped it would be! I was going for a smash-bros style control system, but it didn't really work super well.
Yeah we didn't have a story scene for a... certain moment in the end game. You're right, it got cut for time. :( We also worried that we were making the story too long, so that's why we focused on making more levels, instead of finishing that middle story-beat. But yeah, def would have wanted that to be in there!