By being the first level of Parisian Cat World, it has a backstory. On this backstory, the Old and the Young Scientist that appeared on the other games are working at a restaurant, the story started when the Old scientist's cousin gave him a prototype cat to clean the filthy restaurant, but the cat got out of control after the command "Eat everything." from him.
It is possible to eat the door in this level, if you eat the chair right next to it, right when you complete the level. From there, you would be able to eat the door, but it won't give you any more points.
