Friday Night Funkin is a musical rhythm game in which you compete in free and unique musical battles to test your musical knowledge.
The player assumes control of Boyfriend, a character who must defeat a series of foes in order to keep dating his girlfriend, Girlfriend. A series of "weeks" must be completed by the player, each of which contains three songs. Every week, the player faces a new opponent; however, some games deviate from this pattern by allowing the player to face multiple opponents. The opponent will sing a series of notes (represented by arrows) that the player must imitate using the arrow keys or the W, A, S, and D keys during games. More difficult patterns can be found in some songs, such as when the player's pattern differs from the opponent's or when both vocalists perform a duet.
The user can choose from three different levels of difficulty each week: Easy, Normal, or Hard. As the difficulty level rises, the speed of the incoming arrows increases and the arrow patterns become more complex. For each week, the player's highest score on each difficulty is tracked and displayed in the upper right corner of the week selection screen. There are two modes of play in the game: a story campaign in which songs are played in a linear order, and a "free play" option in which any of the game's music tracks can be chosen at any time.