The core "useful feature" of the game (often found in files like Tasty.Planet.zip ) is the growth mechanic , which allows your character—a ball of "grey goo"—to consume anything smaller than itself to increase in size.

: You can choose from Normal mode (timed levels for medals), Casual mode (no time limit), or Endurance mode (slower growth and higher difficulty).

: Levels progress from eating microscopic bacteria to consuming entire planets, stars, and galaxies.