The principle is always the same: a person has a problem, for example, a little boy is boring, so you have to create an object that solves the problem, in this case, for example, a teddy bear.
You simply open a console and is the relevant text to be a creation of.
There really is a very wide range of concepts and often you have to really think hard, which is the subject fits the situation.
A really innovative gameplay, but in the long run wears something.
Other games such as Little Big Planet is clearly the more for the money.
I recommend the game used to buy cheap and resell for playing through anything, then I've also made.