This is a really great entry. Super fun visuals and sounds. The drill is so OP I love it haha.
The way you're supposed to upgrade your things were a bit confusing at first but I was able to figure it out. I love the balance of the game, the timing one needs to spend on the game is perfect.
The one thing I kinda have a gripe with the game is the fact that I cannot press ESC to regain control of my mouse pointer (I use Firefox for my browser). Every time I press ESC the game immediately takes back control of the mouse pointer. There was one time I was able to pull up the pause menu and regain control of the mouse pointer, but somehow I can only seem to open it once, and I don't know which key was it to open the pause menu as well. So I think you could look into that to provide a better experience for the players to your game page, since I had to ALT+F4 my whole browser down and reopen it to post this review :)
Other than that this was a superb game. Great job!