What the hell is wrong with all of you. Have you guys not ever played any good games yet or what? This game is absolutely terrible. You guys are so easily pleased, I wished they put their skills into making something actually good, not something just to please you zombies.
You will enjoy monotonous work when you grow up if you enjoyed this.
Mining, that is it. Get a metal, go up, go back down, get a metal. There is absolutely no challenge, no strategy and no skill. And no, it doesn't get hard, it just takes a lot of time. A lot of wasted time.
The game didn't seem to be tested (by anyone other than the programmer), and this may be the reason for silly mistakes in this game. A scaling issue of money, upgrades etc. This was the worst issue of the game. You could easily earn money and become rich, buying all the upgrades. If there were more upgrades, and the metals gave less money, making the gradient to robot perfection gentle. When you realise there is no challenge, no game, after getting the new cooling, and going deeper to get a different coloured metal, you realise it really is a horrible game. It doesn't even redeem itself due to original content; All but the very simple, boring and unbelievable story made in 10 minutes is copied. Not even inspiration, literally copying from before.
The developer knew you guys love these type of monotonous games, because you are hoarders, even of worthless pixels. So I can't really blame them can I?