FreeCAD Kids Marble Maze Design

I am looking for a 3D designer to design a "Marble Balance Maze" it needs to be adjustable using knobs (something like this https://www.youtube.com/watch?v=EN-1pWblSAw) to be done on FreeCAD

requirements:
Maze board size - 20cm x 20cm
Wall height - 2 cm
Marble diameter - 12mm
Printing material - PETG
difficulty level - Easy
colour - prefer bright colors for kids
Knobs should mechanically tilt the board - any mechanism that designer prefers, it should be smooth and accurate

Acceptance criteria:
Payment will be released after successful print, assembly and testing of the provided design.