At the beginning of the game, the world is just earth and water, which you can change to be however you want. Once you have the kind of world you want, you can start creating life, for which you'll have a ton of options.
To start, you can form little water droplets that will create swamps. Once you have water, you can create fish as well as little crabs that clean up the sea floor. Here is when you'll start earning points.
The main objective in Gaia Dreams's is to create a sustainable ecosystem in which everything can live together in harmony. This sounds easy at first, but it will be harder than you think.