Comment by racenis
There's literally nothing preventing you from dragging the edge of the engine window and resizing it, or calling the screen resize function from the C++ or Lua API.
That bit about 24-bit color and 800x600 resolutions was mostly meant to be a fun nod to promotional text that you could find on the backs of old game boxes.
The default renderer for the engine is meant to emulate what you could achieve with a graphics card that has a fixed-function graphics pipeline.
I'll do more modern renderer later, for now I am mostly focusing on the engine architecture, tools and workflows.
Great info! That answers my question entirely.