Here are some behind the scenes pictures of CTRL:
Making the puppets 
Otto’s wire and brass tubing armature 
The complete armature 
Making Otto’s clothes 
Green screen test 
Making the NHB 
The NHB and figuring out the size of Otto’s room 
Otto’s room set
And here are all the drawings made throughout the animation:
Brain Bastion advertisement:
Otto’s thought bubble:
The NHB:
The consciousness trip:
Sandro Quattrini's CTRL 