This plays like a bad version of motherlode. It's obvious you've tried to take that concept and build upon it, but most of your improvements fall flat. Not being able to travel straight up means you can no longer have one large shaft to the top, but instead a convoluted set of stairs. Having so many different ores that are all vital to producing separate parts means you're stuck digging around for one specific one until you can progress. To us outside players identifying ores is difficult. Motherlode, on the other hand had you selling ores for a single currency so you could simply buy what you needed. This was a much easier and less convoluted system. All in all I like the initiative, but couldn't stand to play the game for too long.