This is game based of “The Intruder” on Roblox which was most likely based of the FNAF series. In this game you play as Elizabeth Vadales, a girl who cleans the theater after a play. Only four days until the next play, everything has to be clean.
But there’s an unknown figure with one of the masks, she can’t defend herself and has to hide.
You have to hide under the stage once you see the figure near on the cameras. If you stay too long under the stage you’ll lose oxygen, so leave when needed.