Plus 4 - Mastermind is a free-to-play logical puzzle game developed by Walgariant for Android devices. This game is similar to traditional Mastermind with colors, code puzzle, code breaker, and bulls & cows. The goal of the game is to find a 4-digit number code generated by the game engine within 12 turns. During gameplay, players have to guess by using clues from previous guesses to find the secret code.

After each guess, the game engine returns the result in terms of (+) and/or (-). Plus (+) means correct positioning, and minus (-) means incorrect positioning. The game has three different modes: RETRO (CLASSICAL), TIMER (CHALLENGE), and +3 MODE. RETRO is based on 4-digit numbers, TIMER is based on 4-digit numbers with a time limitation of 12 seconds in each guess, and +3 MODE is based on 3-digit numbers.

Plus 4 - Mastermind is integrated with Google Play Services - Leaderboards and Achievements so players can challenge their friends in the game. The game also allows players to choose their gaming style and try to find the secret code in fewer turns or a short time with fast play.