You need to find six keys to exit the room.
Look at the back door. When you see them close up, you’ll also find a key.
On the left side of the floor when you start.
In the lower left corner in the back, use the first white tile on the bottom row of the back wall.
On the right side wall, the sixth row from the bottom. You’ll see a faint key.
On the back wall, right of the door, use the sixth row of tiles from the bottom. At the top of the screen is a key.
On the back wall, right of the door, use the second row of tiles from the bottom. On the right is a key.
Look close at the door again and use the right key of the six to escape.
Game source: A copy of the game was found here on the internet.