LEGO-maniac Anders built this working pinball game out of LEGOs and pure iron will. It doesn’t just react to the ball hitting certain sensors—it even takes score and can keep a high-scorer’s list.

It’s deceptively simple. Pull the plunger by its flying-saucer-shaped handle, and hear that satisfying clack. Watch the silver marble roll around the playfield, and wing it with your flippers. Come up ...