A really original concept. I liked it. The game really lagged when it started raining. Also the text at the end is sometimes not legible since it's behind the background. In the beginning maybe you could make it so the walls break faster, because waiting so long at the beginning just to move anywhere is a big anticlimactic.

It would help to know how much health you have because currently it's anyone's guess.

Once again, great idea and great job!

I like it. I'm not sure how to be more strategic though, I always end up basically just digging straight down