Building World (Mario's Early Years! Fun with Letters for PC)
From the Super Mario Wiki, the Mario encyclopedia
Building World is a world exclusive to the PC version of Mario's Early Years! Fun with Letters. It is one of the seven islands in the game and is represented by a pair of building blocks.
The world takes place in a area of pipes and a background of puzzle pieces.
It revolves around a baseball game setting, where players must sound out three-or-four-letter words depending on what is clicked on. Various animations occur when the cast is clicked on.