Raycaster engine made in Scratch.
A raycaster is a 2D game but it draw something called "rays" on the 2d map, and then calculates the size of each line and the brightness from a first person distance, making it a 3D game. This is a common tactic used in old games like Wolfenstein 3D (Doom is not a raycaster, btw)
Make your map inside of the MAP sprite using the vector tools in the costumes tab.
After that, go to the 3D DRAW tab and set the pen color to the color you want the map. (comments/notes are in the respective sprites telling you where)
Also, set starting position with PERSON sprite as needed.