Aquarium Fish vs Alien

In the game, the player must manage a tank of guppies and other aquatic creatures, and each stage begins with two guppies in the aquarium 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.
This is a virtual pets simulator with a blend of elements from action, strategy, and puzzle video games. The game can be played in five modes: Adventure, Time Trial, Challenge, or Virtual Tank. In Adventure mode, a player advances through four tanks, each with five levels. In each level the player must earn enough money to buy three egg pieces to advance to the next level. During an initial playthrough of feeding fish and fight against aliens, at the end of each level of a tank, the player receives a new pet from the egg. While 28 pets can be earned throughout Adventure mode, each level requires the player to pick three pets. Each pet can aid the player during gameplay. There are bonus rounds where the player can collect shells, which can be spent to place fish in the Virtual Tank.

Recent changes:
Version 3.7 release notes:

New Features:
- Virtual Tank Mode with special fishes
- Players can swipe across the screen to feed fish, collect items and fire lasers at aliens
- Pre-named fishes and Santa Guppy are now available!
- Supports English, Spanish, Korean, Japanese and Thai

Fixes & improvements:
- Fixed behavior of star-catcher and special fishes
- Improved game performance with large numbers of fishes

Changes:
- New Story Time!
- High-level laser power reduced
- Various minor changes