Hi, thanks for giving the game a play. Unfortuantely, I didnt have much time to create a tutorial, but the premise is to consume creatures of the same size or smaller than your wyrm. The growth bar, as well as, the wyrms colors indicate what color of creature you can consume. For example, the starting color is green, meaning the only creatures you can consume are the green ones, until you grow to a new color.
After the voting ends, Ill be uploading a new file that will have many fixes and updates. I hope you will give it another try then.