Boulders!

I got it into my head that that match-3 gameplay wasn’t challenging enough, and that we should add indestructible rocks to the game board. These rocks can’t be matched or cleared, but they can be pushed into empty space once the blocks around them are cleared. I figured this would help encourage a bit of strategizing about which blocks to clear and when.

I got the basic feature working easily enough, but then I decided that it would be more fun to have a giant (2x2-tile) boulder, and that one feature probably took more time and graph paper to implement than the whole rest of the game up to this point. Pretty satisfying to see them finally working, though!