Like minecraft, got Windows 8, broke. Suggestions?

Well, not BROKE broke but I'm saving money for something big so I can't afford unimportant stuff… ANYWAY, a friend showed me Minecraft and I really like it and want to play something like it on my computer but I can't afford to get the real deal. I've heard of a lot of spinoffs and stuff that's made to imitate it, and I've seen demos of some that seem really good, but which one do I want… Are there any good ones that are designed for the Win8 tile interface? And how about with the interactivity and monsters and stuff? That's pretty much all I'm looking for, aside from it being free or really cheap.

You should go to a website called:
mineshafter.net/.com, I don't remember… Anyway; you install it to your desktop like any other computer.