So good news, the game works, it does stutter a few times, where the frames drop to 0 for a few seconds, but otherwise its fine.
Did reach a moment where could not pickup more stuff, and also did not have enough money to buy anything, so i guess i was done with the game at that point? xD
The art style look good, and gameplay reminds me of the games mentioned in your GDD (especially Motherload)
The Theme isn't really present in regards to the gameplay besides the upgrade system, though that is not complete it seems (or i did not mine far enough).
Overall job well done on making something fun, interesting and playable, good job.