In a way, I suppose. You have to mine the rock, copper, silver, or gold, and then you get to try stuff once you have it. There are other metals, and even gems, but I'm still on the newb island of Haven.

I'm also looking at another game in (alpha? beta? who knows...) testing. It's called Endless Online, and it's version 0.12, and I still don't know what to make of it.

Terraworld is at least temporarily out because they lost their server, otherwise I probably would not have found either of these things.