Zoombinis: Island Odyssey was the sequel to Zoombinis Mountain Rescue.
In this game, the Zoombinis discover that they left the moths to die in their native land of Zoombini Isle. So they take a boat and travel to Zoombini Isle, which is now completely empty of the Bloats (who made the land barren and then moved on). They must complete different puzzles, such as growing berries and breeding butterflies, to eventually set off a chain reaction that will restore the entire ecosystem of the island to its original glory.
This is the first game to incorporate science in the puzzles, which include intersection of rates, decoding, astronomical time, Venn diagrams, and Punnett squares, as well as some reincarnations of puzzles from Logical Journey. The graphics have again changed, and the Zoombinis' features are no longer important to gameplay. Here, they are fully 3-D.
To win the game, the Zoombinis must take care of the Zerbles, feed them, and then release them into the wild. Once the Zoombinis get all of the 224 Zerbles into the wild, the Zoombinis head back to Zoombiniville, and the game is won.
Source: Wikipedia, "Zoombinis: Island Odyssey", available under the CC-BY-SA License.