Hmmm, they are a bit confusing since I took inspiration from katamari damacy and I wanted them to be weird, it's basically holding ZL+ZR, then holding down on the left stick and cycling XABY repeatedly to charge. You also gotta unlock the ability to shoot different balls for different targets.
I'm probably adding a tutorial post-jam tho, I'm disappointed that I couldn't make the gameplay clear enough :c Thems jams, I suppose.