Lingo is nice and simple, and with plug-ins, is very flexible. If your brother is used to BASIC, Lingo would be a much gentler step that C#. Director 8.5 even has 3D support and networking.

The simple game is made using ArduPy (which is MicroPython combined with Arduino APIs) using Seeed Studios’ Wio Terminal, a small microcontroller development board with integrated screen ...