@cameronrobinson Well, for one thing, "redstone": is there any real-world substance (or combination of substances) that can emulate its properties? Also, the rarity of diamond: does Minecraft accurately represent how rare natural diamond is in the real world (if the diamond in the real world were evenly spread across the world, which of course it is not)? What about the other minerals, is Minecraft in any way geologically accurate? The special dimensions of the Nether and The End could also bring up questions about interdimensional travel, and Endermen bring up more questions about "ordinary" teleportation. Of course, the biggest question would be about Creepers: how would they work, and how could a hostile organism that seeks out opponents and attempts to blow them up suicide bomber style actually work on an ecological scale (or in other words, "why don't the Creepers go extinct?")?