The company is adding avatar-based, 3D video chat to its virtual world in an effort to expand its audience—and to keep the kids around as they grow older.

Dream Six Codes may be exchanged for free gifts that will help players along the way, such as summons and jewels.

At 26, Andrea Fletcher has worked for Google, Apple and Roblox but says her career in software engineering really began with her childhood love of logic and math puzzles.

Andrea Fletcher has already worked for Google, Apple and Roblox. Ms. Fletcher, a full-stack software engineer at online game platform Roblox, had a childhood love of logic puzzles involving math.