Favimon is a monster-catching RPG loosely based on the Pokémon series, in which all characters are favicons, the small 16x16 images associated with specific web pages. The player starts with a single Favimon, and types in the URLs of other sites in order to strengthen their own Favimon and build up their collection. Each Favimon has at least one class, typically associated with what kind of content its website provides, which affects what attacks it can use. For example, websites related to books and reading will produce Favimon that can use attacks such as Papercut and Required Reading.
Battles are turn-based, and involve the wild Favimon and one of the player’s Favimon battling each other until one or the other is defeated. If the player wins, they catch the wild Favimon, but if they lose they must start a new game. All stat changes that occur during the battle become permanent, and all defeated party members remain dead.