Arrow keys to move around. When the boss is not trying to crush you, shoot at you, or swing a club at you, and is just randomly gliding around the bottom half of the screen, jump on his head to deal damage. Otherwise do not touch him or you will take damage. Obviously, don't lose all your health, and get rid of all his health.
Health bars by @falkimore and @griffpatch SPAM THE FLAGGGGGGGGG btw yes his giant swinging club saw is possible to avoid >:]
