Spam dat green flag, and the arrow keys are used to move. To beat the boss, you have to avoid all his attacks without taking damage, then touch the button that appears when you do. Then, repeat until he's at 0 life.
This is just a platformer that I decided to make. I also only used what was in my back pack, so I don't think I have to give any credit! However, I should probably mention that the songs are from Geometry dash. UPDATES: 1.1: Better bouncing script for when billy touches his own element.