It supposed to teach you that you need to have at least an adjacent bulb to toggle their states
Viewing post in On Or Off jam comments
I think a tutorial for all the mechanics as well as some sort of visual indicator for the bulbs you can't click (maybe a box around them or something) would go a long way. When I got to the dots, the first three levels I accidentally completed in a click or two and had no idea what they actually did, which ended up getting me stuck on the next level.