This game was phenomenal. Simple idea, executed perfectly. It really reminded me of Motherload, which I put dozens of hours into as a kid on Miniclip, You all really captured the same vibe: dig down as far as you can, buy upgrades, see if you can get further the next day. Even the ending was a great add, and adds that bit of mystery and accomplishment of how it feels to get really deep that you've unlocked a crazy mystery.
Agreed that tuning is not flawless, but honestly, I loved that for the game jam. I failed a couple times (which is still hilarious and fun) until I cheesed it with ladders and TNT and got to the ending. I think if you all embraced that idea and made a game where buying TNT and Ladders was just the logical next step in progression, added in more layers and story, and fleshed it out more you'd have a fully featured game I'd pay money for.
Also, love the dog addition. It's just the kind of fun you should be adding in a jam. You all rock, great work!