Let me note that compared to Origins, Spore Creatures is more challenging. There are 20 levels spread out in 4 different environments, and to complete each level successfully the player needs to collect a certain number of points or fulfill quests. There are boss battles for example, that require some ingenuity in order to emerge victorious.
The game is unstructured enough to allow the player freedom to explore the environment. Because the environment is populated with flora and fauna, it’s more difficult to move around especially using accelerometer controls. While the tilt controls run quite smoothly and can even be calibrated to suit one’s preference, the small physical space to work with makes it difficult to move around freely.