Complex sentence: Each creature must eat other organisms to grow bigger so that it can go deeper under water until it finally reaches the bottom area, when it eats the ending piece, the game returns to the top so that the player can start over as a new creature.
Split into simpler sentences: Each creature must eat other organisms to grow bigger so that it can go deeper under water until it finally reaches the bottom area. When the creature eats the ending piece, the game returns to the top so that the player can start over as a new creature.