It flows in areas of space in the levels of Rockitty, and it appears sometimes in a stream-like formation. Sometimes it may also be seen in large patches that are a definite shape. The milk itself is a creamy white colour, with bubbles floating around in it.
When Rockitty enters an area with space milk, it will cause its rocketing to slow down slightly as it flows in the direction it initially traveled in. With this, the player can change Rockitty's direction while rocketing in the milk. This can be done until Rockitty exits space milk. Live fish reside in the milk, which Rockitty can eat for a certain amount of points.