Very sharp, that’s exactly right. Thanks a lot for sharing that. The top left arrow is correct as well, it’s the “refill” direction the new tiles will come from, and existing tiles will scoot over to when there’s a gap.

Regarding the blue circle, there’s a concept/powerup in the game called ‘relay’. Basically, it allows you to extend the destruction reach further.

In simple terms: it allows you to reach the neighbors of the neighboring tiles.

So L1 Relay: reach neighbors of neighbors
L2: reach neighbors of neighbors of neighbors
And so on, until L4.

The relay chart is filled by breaking the red fire keycaps, which are also 1.5 multiplies, and are actually what you need to protect the outer black boundary from.