The gameplay of Friday Night Funkin game is very simple. You can play FNF game with just 4 keys which UP, Down, Left and Right.
When you first open a game on your device, You first have to select mode. There are three modes in the FNF game which are Story Mode and Free Play Mode. After that, You have to select weeks. Now select the hardness of the game. There is three hardness Easy, Normal and Hard mode. Now music will start playing and you have to sing by Up, Down, Left and Right buttons. If you play music well, You will win.