How did you implement the theme?
The whole game is built on light. This is played out in terms of the plot (the main characters are light sources) and in other aspects. For example, the main character is a lamp whose fuel is constantly decreasing (and, accordingly, the level of light) and when it becomes completely dark, the main character dies.

How did you add the special object?
Throughout the game we can see checkpoints in the form of houses. We can open their curtains to illuminate the nearest area and restore health due to light