Nice work! I like the dual purpose nature of the blowtorch and how you have to repeatedly change how you use it to best suit the situation, though once you start getting asteroids everywhere you basically just have to start repairing since you can't keep up.
I think one change that would make this a lot more fun is being able to aim the blowtorch up/down/left/right so that you don't have to be on the side of a block/asteroid to repair/destroy it.
Also, you can go off the screen (Most people wouldn't, but I got knocked off the screen by two asteroids hitting me at roughly the same time)