Insaniquarium!

About

Insaniquarium is a virtual pets simulator with a blend of elements from action, strategy, and puzzle video games. In the game, the player must manage a tank of guppies and other aquatic creatures, and each stage begins with two guppies in the tank. Guppies and other fish drop coins, which can be collected by the player and used to purchase fish food and upgrades, such as more aquatic creatures, food that can keep the fish full for a longer period of time, and laser upgrades to repel attackers. The coins will disappear if they reach the bottom of the tank. Each creature must be kept alive by feeding.

Source: IGDB