The Grow Game is a flash game where you add items to a planet and see how they react to each other. Depending on what order you add stuff will depend on the reactions you get. There is a specific order that you have to add the items in to get the top score.
Also check out grow island.
I beat the game with the score of 20,000.
(Hint: Experiment with what items react with others and the order you add them.)