After looking a bit at your engine, I have a bit of criticism to make, if you don't want to hear it, don't read any further.
- Why are some classes not marked as static when they obviously should be? (RCD_Graphics.AdvancedImageTools as an example)
- You are using 2 different code styling types, example: "RCD_Graphics.RCD_Image.Draw_Image" conflicts with "RCD_Graphics.RCD_Image.DrawPixel" in terms of style (that underscore) also let's not forget about "CD_Graphics.RCD_Image.bit" which is a lowercase style instead of the usual uppercase style.
- The keyboard class is located in RCD_Graphics, although it's an input module.
- Your "Scene" class has 2 functions ("FrameDraw" and "TickUpdate") you should just leave it as "Draw" and "Update". (This is just a personal complaint, it doesn't really make a negative impact on the efficiency)
- While I'm on the commenting on the "Scene" class, why don't you just add a type template to it so that the "Result" function would give out a specific value instead of needing to convert it to a specific type? (This isn't a complaint either, it's a suggestion)
- Lack of documentation. (Although it's easy to understand what each function does, it still needs documentation since some people may get confused)
- Your copyright is full of errors. (Such as "no reverse engineering" which engineering is misspelled (even if it wasn't, that won't be sufficient to legally stop decompilation of your engine))
I'll add some more criticism as I find things. (I really haven't even begun to look into it, this is just glancing over each class not looking too much in detail)