Stan is a police officer from the series known as Nightmare Cops, but he does not always use guns to fight, sometimes he uses music, just like today when you and BF face off against him in a rap battle on the following custom songs:
Stand up to cops with music!
You can choose to play this game in either the story mode or free play mode from the main menu, and with both options, you have the same end goal, which is to reach the end of the songs by playing all their notes.
To do this, watch for when arrow symbols above BF are matching, and at the same time press the identical arrow key. If you miss doing that too many times in a row, you end up losing, so don’t let it happen, but WIN!