The goal of Osmo Numbers Education (the original version) is to collect all of the fish. You can do this by unlocking all levels and trying to get the highest score possible. There are over 90 fish that you can find in the game. Each mode/depth contains different types of fish to discover, including tropical fish, food fish, instrument fish and even monster fish.
The new Osmo Numbers app adds more sea animals and more game modes.
Find more information in our PDF guides to the new Osmo Numbers app and Osmo Numbers Education (the original version of the app).