Every part in its place

I have a deep fondness for puzzle games and finding out how things interact, and the game Grow (both the original and the games that followed) does this better than any other game I've found. The goal is to find the optimum order to activate the different elements, but since everything affects everything else, this is WAY more enjoyable and challenging than you might think (after all, if you don't get the lake big enough before the sun shows up, you end up with something of a desert). I wait with perpetually bated breath for the next instalment.