I didn't know what I have to do. I couldn't get the blue door to open.
Viewing post in The Unforgettable Adventures With Dr Hans jam comments
The blue door cannot be opened, it's purely for comedic effect.
In the main menu, you can find the help button on the bottom right (all the controls are listed there).
The objective is to move the light brown boxes and position them so that when you control the doctor (green player), you can make it till the end.
I hope I explained it enough, if not I'll gladly elaborate more :)