Just a point that may or may not be obvious for getting out of the box at the start of level 72.
When you do successfully make a bubble DO NOT move left or right, just jump on your bubble, then hold A to bounce on it and blow more bubbles and you should be out the box in no time.
Actually blowing seems impossible at first but its not too bad once you figure it out.
You need to jump at the wall then change direction (bearly move the stick past the centre) and blow a bubble.
It's all about an incredibly slight movement.
And the get the happy ending you just need a 2nd player on lvl 100 which you'll probably need anyway to clear the boss