The line separating work and play has always been blurred for Roblox teen millionaire Nate Colley. As a kid with an iPad growing up in a Nova Scotia trailer park, he could have almost any job in the company’s online game world — a food server in Work at a Pizza Place or a logger in Lumber Tycoon. He just couldn’t be a fisherman.So in between homework and a part-time job at a Chinese restaurant, Colley invented Fisch, a popular game on the 144-million-member Roblox Corp. platform. Today, at 19, h...