Petri is an engaging puzzle game for Android where players are tasked with growing a cell culture in a Petri dish. The objective is to deposit "good" cells that will grow and divide, spreading across the dish. However, players must also contend with the appearance of "bad" cells from the ambient environment, which they must battle for control of the dish.

To aid in the challenge, players can utilize various tools such as lasers, temperature-control, penicillin, radiation, bleach, and intentional phage infections to fight off the bad cells. Additionally, spontaneous phage infections may occur, posing a threat to the player's colony that must be fought off.

The game features level progression divided into stages, with each stage consisting of a series of rounds. As players advance to higher stages, the difficulty increases, and each round introduces variations in gameplay. These variations include different round end-conditions and possible bonuses, requiring players to adapt their strategies and approaches for each round.

One standout feature of Petri is the online global scoreboard, which allows players to showcase their success to the whole world. Whether through the app itself or the website, players can strive to improve their high scores or aim to surpass other players' scores for dominance on the global scoreboard.

With its high replayability, Petri offers players the opportunity to continuously challenge themselves. There are no secrets to uncover, but players can keep striving to improve their scores or compete against others for the top spot on the global scoreboard.