Great work to pull this off so quickly. Love the art and and the lightning reanimating a zombie is a great hook.
Felt so silly at the start though. Spent a good 30 seconds thinking your game was broken because I was clicking all of the tiles really quickly and nothing was really happening. Clicking once plays an animation like something was happening, and then another flash happens a few second later, but it doesn't progress the game. Should probably have the cracked texture happen after the first click, not the second, or at least update the wording to indicate multiple clicks are needed. It's so easy when you know how you're meant to play your game to forget that it might not be obvious for someone else.