Hero.Coli is a single-player 2D top-down adventure game where the player controls a bacterium to explore a fantasy aquatic world. The user directs this bacterium, a stylized Escherichia coli, to collect and combine functional DNA fragments in order to engineer and control its abilities. More precisely, the user can craft and equip genetic devices, including one that enables the bacterium to increase its speed, and another genetic device that makes the bacterium blink. Again, the functionalities obtained by the bacterium in the game mimic real genetic circuits with similar functions.