Undercover: the Forgetful Spy is a game of spies and traitors where players have to guess who the traitor is. Undercover: the Forgetful Spy can be played online with other friends, or in offline mode using a single smartphone.

Offline mode has a minimum of five players. Among the characters that can be chosen are civilians, Mr. White and an Undercover. All civilians receive the same word, while the Undercover receives a similar word (e.g., cherry and strawberry). Mr. White receives no word, simply the information that the player is Mr. White.

The civilians' goal is to uncover and eliminate Mr. White and the Undercover. The latter has to survive to the end by pretending to be a civilian, while Mr. White's goal is to guess the secret word through the descriptions given by the civilians.

For example, if the word is "strawberry", they have to say its color, if it has pips, and so on. The Undercover will have to say characteristics that they think might fit the civilians' word, based on their descriptions. But they must be careful or risk being discovered by the real civilians.

When the Mr. White player is discovered, they have one last chance to guess the civilians' word. If they get it right, they win. If not, they lose.

Civilians may also have special roles:

- Goddess of Justice: If the vote is a tie, the goddess has the final say in deciding who to eliminate, even if she herself has been eliminated.

- Lovers: Two players are in love. If one is eliminated, so is the other.

- Mr. Mime: Each round, a player must mime their word instead of describing it.

- The Avenger: When eliminated, the Avenger can take another player with them.

- Duelists: Two players are in a secret duel. The first to be eliminated loses two points, and the other wins two points.

Both downloading the Undercover: the Forgetful Spy APK and playing the game are free. But, if you want to unlock new words for the civilians, you'll have to perform certain tasks, such as playing with the special characters or watching the video with the rules.