Terminus Main Quest

Hi! Yesterday while playing Terminus with my friends we accidentally started doing the Easter Egg. But what I don't understand is this: Yesterday the Round Cap was active and there was a step by step indicator on the top left of the screen showing how to do the Easter Egg. I have no idea how we opened this indicator. Does anyone have an idea? We found ourselves in it without even knowing it was an Easter Egg. It even showed us that we had to shoot the fuse boxes.