Players move through a series of worlds using a small number of sentient humanoids to build small bases and to stun, kill, research, and ultimately breed a variety of animals. Plants are also important, as different plants can be grown and harvested for different purposes. Players must use the various plant and animal species available to them (as well as hybrid animals) to deal with different environments, enemies, and tasks. For instance, a crab is a good armored defender, while a mule is a perfect detritus transporter. The two can be bred to form a creature that is well armored, but also suited to mule work. The more a particular species has been studied and created, the more effective future individuals will be.
The primary resource of the game is goop, which is derived from all kinds of biomass.