Cubes is a work-in-progress open-source block game (that is, like Minecraft) where the blocks are made out of blocks; in principle, you should be able to build a complete custom block game from scratch simply by building the appropriate block-set, out of blocks. As I mentioned earlier, I'm doing a project on the HCI for this game. I need data.
If you think you might be interested in playing my game, or if you're a current player of a block game (Minecraft, Terraria, FortressCraft, what-ever),
please take this survey. I assure you there are no “On a scale from 1 to 5” questions in it.