You are a small thing that ran away from the laboratory. Now your aim is to become bigger and consume everything on your way.
In the main menu you will see a bunch of different levels. After you complete one mission, the new one unlocks for you. In the beginning of every mission you spawn on the table surrounded by broken glass, various laboratory items and other rubbish. Also, you can see little colorful spheres around the entire location.
Consume them to grow bigger and make the special line full. It shows you your current progress, so take a look at this line sometimes. On the more difficult levels the huge creatures start to run around. Huge white rats and green frogs are the first enemies. But if you can eat them, feel free to do it.
Enjoy Tasty Planet and eat everything on your path.