Tasty Planet: Back for Seconds

The story of Tasty Planet: Back for Seconds begins with the tiny ball of grey goo being fed in the laboratory and growing in size until it can consume the time machine. At that point, it is sent into the distant past, more specifically the Late Cretaceous period, and later its journey continues through Ancient Egypt, Ancient Rome, Feudal Japan and even the distant future. Through all of these periods, it will do what it does best: eat anything smaller than itself and grow as a result, eventually reaching the size of mountains, planets or even entire galaxies, the camera zooming to reflect the changes in scale. Each item eaten has its name listed.

Early levels are simple, but later the hungry goo has hostile creatures to avoid, each hit causing it to decrease in size. "Food" respawns, however, so it will never be impossible to find enough to reach the required size to finish the level. One of the game's modes, appropriately called the Timed Mode, introduces a time limit and also grants medals based on the amount of time required for the completion of each level, none of which exists in Casual Mode.
A number of levels with special goals also exist, such as requiring the goo to collect a certain number of a particular item, or to navigate a maze and find food small enough to eat until it can chew its way through the maze itself to the next section, or to use larger items to protect itself from attacks, or to defend one of the sides involved in a conflict, or even to go against enemy grey goos.

A new addition compared to the first Tasty Planet is the two-player mode, where each player controls their own goo, allowing for either cooperation or competition through all levels of the game. A few special two-player levels require cooperation, however.