Roblox is a game creation platform on PC, Mac, iOS and Android with 7 million players a month. Next month it comes to Xbox One to take on the likes of Disney Infinity and Project Spark.

But that's not the case for Lithuanian 17-year-old Laimonas Mileska, or Loleris as many know him. Mileska has been creating video games through a platform called Roblox for about five years under ...