I must say a thoroughly addicting game, I mean I spend 4 hours playing it. Fantastic.
If I have one critique it would be that I would have liked it if there was a counter in the corner to show a count of how many of one item you have.
This is less of criticism and more of a suggestion, getting the rock to drop the stone for the pickax seems to have a very VERY low chance. I feel like I spent 45 more minutes necessary just hunting down rocks.