Flying Machine

Balloon Goo is making both the gates and the Goo structure buoyant.

Buoyancy is one of the physics based aspects of World of Goo. Buoyancy refers to whether or not objects float. An object is said to be buoyant if it floats. In World of Goo, there are two main types of buoyancy: buoyancy in water and buoyancy in air.

Buoyancy in water

Almost all Goos are buoyant in most types of water, and are usually found floating on top. Goos rarely sink. Submerged goo will almost always spring back up to the surface, as seen in Water Lock. There are a few exceptions. For example, Goo is not buoyant in the orange water at Genetic Sorting Machine.

Heavier goo structures sink lower, but resurface faster and higher as a result. Thus, the heavier a structure is, the bouncier it is in water.

Buoyancy in air

Unlike water, very few goos are buoyant in air. Balloon Goo is the most common of these. This type of buoyancy is often used to combat gravity. Structures with more weight become less buoyant, and it takes more Balloon Goo to make them float. The more Balloon Goo is attached to a structure, the more buoyant it becomes.


  • In Flying Machine the player must make a goo structure buoyant enough to fly to the pipe at the top of the level.
  • In Fisty's Bog the player must use Balloon Goo and Black Goo to maintain an equilibrium - the structure must be not too buoyant, nor too heavy.

Eyeball Goo and buoyancy


Eyeball Goo

Eyeball Goo has very irregular properties of buoyancy. In the air, it is buoyant enough to lift structures into space, but in the water it becomes so heavy it acts as an anchor. This is a reversal of the physical properties of both World of Goo and the real world.