This is due to almost each of the songs is only under 30 seconds long, with the only exception being the Main Menu music which is still only 45 seconds long. One Night at Flumpty's soundtrack consists of 6 tracks (5 if The Call which is dialogue is not included), and is only a total of 2 minutes 28 seconds long. Beating this mode will unlock a star on the main menu. Once the main night is beaten, the player unlocks the Hard Boiled Mode, which is essentially the second night with each characters having much higher difficulty AIs. After that you will get jumpscared seconds later. When the door-using ones (Flumpty, Birthday Boy Blam and the Redman) enter your place they disable the light buttons, but you can still use the doors. However, the doors only have a limited supply of power, so the player must be strategic in how and when they use them. The player must stop the characters from entering their room and killing them by closing the doors.
The gameplay is very similar to that of Five Nights at Freddy's, as the player is situated in a single room they cannot move from, are in control of two electrically powered doors and lights placed just outside the doors, and must keep an eye the characters' movements with a monitor and several cameras stationed around the building. If you survive the entire night, you will have a new friend! If you don't, well. Survive till 6 am by avoiding Flumpty and his friends.
I hope you are good at hiding, because I am coming after you. I brought you to this special place so we can be friends. I'm immune to the plot and can transcend time and space.