Layer 1 - assembly to get the system to boot and communicate with hardware.

Layer 2 - C to schedule tasks, manage memory, provide filesystem support.

Layer 3 - C/C++ to provide a graphical user interface framework.

Layer 4 - C/C++ to render web pages.

Layer 6 - C/C++ to implement a Javascript VM.

Layer 7 - Javascript to implement a Lua interpreter.

Layer 8 - Game engine written in Lua.

Layer 9 - Game specific code written in Lua.

I wonder how much bang per Mhz this setup provides.