The light in the scene was okay. There were a few small lanterns that guide the player through the scene. I did not want to change these too much because they're very important to both the level and the atmosphere of the scene. There was one big exception though...
As you can see every now and again the whole scene is colored by the light of the lighthouse. The lighthouse light is there to guide the player and give atmosphere, but it really does not need to cast shadows on the whole scene.
Afterwards the lamp of the lighthouse does not periodically light the whole scene anymore. There is no in game difference.
I also found this random spot where for some reason unknown to me there were 2 lamps pasted over each other.
I deleted the smaller lamp and it made no difference to the scene. I probably just made a small mistake here and accidentally put two lamps where there should be one