With parties like this it’s best to turn to the experts, the kids. They know everything. I’ve also learned that if you can get the general idea, they will fill in the gaps beautifully, and bring the entire party to life.
Use green, black, and brown as your color scheme, and if you can find them, use square plates for food.
Everything in the Minecraft world is comprised of pixels, which is kind of cool, because it can be made out of or on squares. One of the fun things I did for a centerpiece was simply print out two pictures of Creeper on a sheet of cardstock, folded it in half and laminated them. I cut the bottom to make a pocket and slipped the art onto a dowel. I look a coffee can, covered it with green paper (you could add some pixel squares if you wanted, or a logo), filled it with sand, and stuck the dowel in the middle. I inserted a few pieces of sparkly star wire around the dowel base, and called it done.
Using Avery 1 x 2 5/8 inch labels I made TNT labels for Now or Later candy cubes. Each cube took two labels, and they were so cute when they were done. Likewise I make Creeper Candies that I wrapped around laffy taffy pieces.
My sister made the most amazing pinata ever by stacking and gluing boxes together. She then covered the boxes with decoupaged green tissue paper. When it was all dry, she cut the bottom box open, filled it with candy bags, and taped it shut. The pinata itself was too hard to crack open, so the bottom could be released once everyone had their turn. This made the birthday boy very happy, as he “conquered” Creeper.