This is coming along well
The movement and drilling was good.
Here are some recommendations I have (which you can ignore if you choose to):
-Have level number default to start the level on 1, as when I first tried it was on "0" which wasn't actually a level.
-I think since the controls are very simple you may as well mention them on the start screen.
-The sound for gaining a battery doesn't sound that special
-The enemy rock things and the non harmful rocks are too similar in appearance, it was hard to distinguish between them.
-The recharge is perhaps a bit too slow?
"-Have level number default to start the level on 1, as when I first tried it was on "0" which wasn't actually a level."
Whoops. I'll try to fix that. It shouldn't be too hard.
"-I think since the controls are very simple you may as well mention them on the start screen."
Meh, I might consider that.
"-The sound for gaining a battery doesn't sound that special"
Yeah, I'll see about changing that.
"-The enemy rock things and the non harmful rocks are too similar in appearance, it was hard to distinguish between them."
I'll see about changing some colors around.
"-The recharge is perhaps a bit too slow?"
It's meant to be like that to encourage you to conserve drill power.