Nice idea! I liked balancing in my head how many cells are going to ignite vs how many I can extinguish. I also liked the moments when I had to make "controlled burns" to guide the flame somewhere I needed.
I'm wondering how a version of this would work on a graph where nodes could have arbitrary number of neighbors.
Clicking on the same cells over and over again just to make tiny progress gets quite tedious, especially on later larger levels. I feel like a worker placement system could improve the experience, while being mechanically similar. You would have workers instead of clicks, and placing worker on the cell would prevent it from being ignited.
I agree with the comment about the colors, they seem broken. I lost a lot of progress on level 13 a couple times because I extinguished the wrong switch. It would help to have distinguishing symbols, simple shapes or patterns in addition to color coding.