After clearing the levels 1-6, you unlock the boss on level 1-7 and you are able to fight Hansel and Gretel. This boss has 3 lives and repeats his attack pattern 3 times.
Tips & Tricks:
-The boss has always the same pattern;
His first attack consists of him slowly moving forward with his body. When he does this, make sure you change the world in order to have the moving platform under you poking at the right moment Hansel & Gretel.
After you succesfully hit Hansel & Gretel with the platform, press
to twirl over them. They will start to crumble and begin with a rolling attack from one side to the other. Make sure you stand right in a corner and as soon as they are about to roll in, press
to avoid getting hit.
After they finished rolling out, they disappear and appear above you on the stones and start throwing rocks at you. No special tactic is required here, just try standing still and use the dashing
After this, the pattern repeats.
I have included my gameplay down below to demonstrate how to use the strategy against this boss.