In this tutorial, we darken the room using a darkness sprite that follows the player. We also set up torches that angle out from the walls, and when the player collides with the torch, the room gets lighter and the player can walk around with the torch.
After a few seconds, the light begins to darken until the torch goes out, and the player must walk around in more darkness.
This was a fun mechanic that required extra coding because as long as the torch moved with the player it was triggering the collision event every step.