Alright then, thanks for zero information. You can forget it if you think I'll be helping you get sponsors for your game when you can't even answer basic questions. Consider my involvement as a tester over, you may as well delete username Kalgoorlie Resources from the system, they ain't coming back.
For what it's worth here's some feedback:
The game itself is quite interesting, somehow you always think more is going to happen but when it doesn't it's just same old, same old. There's no incentive for people to play the game and even less incentive for them to use real BTC to buy anything in-game. The basic free polishing sponge seems to work just as well as the polishing disk that cost 0.04, plus polishing gives you something to do while you dig for coins... but really, after a few clicks you're already over it and off looking at another website or have wandered away from the pc. There needs to be some clear incentive for people to spend money, like the polishing paste, tell people that it will 'clean 10 coins at a time' or something that makes people want to buy it.
The basic ideas behind the game are quite good and you could advance the physical mining metaphor further, perhaps by allowing players to buy physical claims or territories, like they did in the old days with gold rush mining stakes and like they do now with formalised mining leases. That would allow you another mechanism to encourage people to spend money on the game and if you made different mining territories that changed regularly, had different criteria and were limited in number it might attract people to use real coins to buy them. If you wanted to push that more, you could allow these territories to be transferable, to enable players to buy and sell territories to other players. Then add a chat feature and it gives a reason for players to speak to each other, that itself builds competition and interest in the game:
"Selling 'North California Sierra Navada Gold Stake 10 x 10 squares, Claim Grade: Good' for 0.5 BTC"
You make sure that only the player owning these claims can mine on them and even when they are partially mined, they could still be able to be sold:
"Selling 'South Africa Driefontein Gold Field 15 x 15 squares, Claim Grade: Very Good' I've mined 15 out of 225 squares, selling for 0.75 BTC"
Also, researching the technologies was interesting enough, but you're going to have to have clearer capacities between them. Using the basic spade, players understand that they are going to be slower when mining, but when they've upgraded to a pick or a mining badger, they expect more mining efficiency, that just wasn't defined enough. When you're looking at this and making the adjustments, consider also charging a fee to upgrade to the higher mining equipment.
Anyway, you've got 60% of a game concept and I'm sure with some work and some feedback from others you'll be able to improve it further.
Good luck.