Flow based gameness

My group (Jac, Will and I) are creatin a game that is based with the same gameplay style as "Flow". We're making ours based around art and the four elements and our first idea was to travel trough art history (however this was then deemed too big for what we were doing so it was scrapped).
So, taking a simpler approach we've decided to alter art history into restoration, where art pieces in a museum have been damaged by the elements (earth would make it dirty and cruddy, fire would singe the work etc) and you've got to restore them to their former glory. On top of this, we're going to base each element on art styles around the world (Water would be Asia due to their watercolour paintings, Fire we'd assigned to Africa, etc).
Each element is good against one but weak to another - Water can put out Fires but can get absorbed by the Earth Clods.

A mock up of the four Elements - Fire, Water, Earth and Air