So let's start with level_73 first.
On the screen you will find purple color dominate the area.
And What you have to do is to find 5 differences on the left door and right door
Look at the picture and you will see 3 items on the left door and 2 items on right door
100 Doors level 79
Be patient please because we are still waiting the update. When The game maker team release the puzzle we will try to provide the guide of 100 doors level 79 for you.