Flower, a New Game About Nature

"Each level takes place in a different flower's dream as it sits on the windowsill of a dull city apartment. As the player progresses through the game, the apartment and city gradually becomes more vibrant and colourful, until it climaxes at the 100% completion mark and the cityscape is replaced by a vibrant field with mountains in the background. The player guides a petal through brightly coloured, abstract fields by tilting the motion-sensitive controller; pressing any button on the controller gives a speed boost. The aim is to guide the petal into other flowers in the field, triggering an explosion of colour that spreads through the game world." Wikipedia: Flower