Fishdom

The object of the game is to solve puzzles and earn coins to set up and decorate a virtual aquarium. Using in-game currency the player is able to purchase different species of fish, decorations, and "comfort" items to make the environment more pleasant for pet fishes. Filling all of the three meter gauges measuring the progress will unlock one of the trophies: bronze, silver, or gold. Adorned and themed tanks can be used as a smartphone screensaver.

Levels are based on a standard for "match three" mechanics: the player swaps two adjacent gems to make matches of three or more. Each of the rounds takes place on a different grid and poses a challenge to earn golden tiles by matching gems at least once over each one. Some of the tiles are locked and have a different color; to unlock them the player must match gems consecutively over multiple turns. When three or more objects are matched simultaneously, one of the bonuses appears: firecrackers, depth bombs, dynamite charges, or lightning.

The original game was released in 2008 for PC and was adapted for smartphones by 2015. In addition, several sequels have been launched.

Fishdom ranks among the most popular games from developer Playrix and received generally positive reviews. iParenting Media named Fishdom H2O: Hidden Odyssey one of the Greatest Video Games of 2009. According to the analytics of Sensor Tower, Fishdom was a top game in the category Puzzle&Decorate with around 15.6 million downloads in 2020. The game was ranked 16th on the annual App Store list of the best free games (8th for iPad, 19th for iPhone). According to Statista, the game was one of the ten most downloaded puzzle gaming apps as of 2021.