It kept me Entertained
It made me busy for a few hours, and it was pretty fun...
It seems like a fun game and could be really fun if it was improved a bit.
Somethings I noticed that could use a bit of tweaking:
A bit too much of solid rock and stone in the lower mining areas.
Dynomite should do a bit more of AoE damage, or make a sort of mega dynomite that will give a larger AoE, but at a higher price (Maybe?).
There's a Glitch or two I've noticed:
Repair man has a misprice, it says one number, but really means a number 300+ higher.
To wrap it up, I think it's a fun game that could use a bit of touch-up, nice work.