Looks good, feels good just quite satisfying and fun well done. I seemed to be able to 'go infinite' pretty quickly by upgrading the coal -> fuel path, from there I ended up with so much money so fast I ran out of upgrades to buy before I was even getting ~20% of the way through the dig. Then the challenge is building a machine that can make it all the way.
Well done great work this is fun and impressive bit of work for only a week