I am working on a prototype game with several funny/visual effects that the player can trigger. The player can be quite creative in the way to use or combine these effects but it seems impossible to make detect/evaluate this creativity by the computer.

So, from a game design perspective, I wonder what could be the features to drive the players to be creative (experiment various combinations).

For the moment i think about "Draw something" where the result is evaluated by other players. I think about levels designed by "Little Big Planet" players but this aspect is out of the core game. I think also about "Minecraft" but I do not understand really how this game encourages the people to be creative (except of the open world).

Please tell me if you have any ideas, articles or references that could help me coping with this problem.