alt Hacker NewsOooh, I LOVE this! Especially the ability to "Overriding emulated code with C# code" I had a similar idea years ago (https://gabrielgambetta.com/remakes.html), not in the context of a debugger or reverse engineering per se, but in the context of remakes and "special edition" games. Not entirely surprised that this is a byproduct of OpenRakis. Amazing work!
I tried doing something like this about 15 years ago but specifically for audio by routing NES NSF rom audio data (square, triangle, PWM, etc) to virtual midi cables attached to VSTs so you could play any old school Nintendo game with modern instrumentation. Was a pretty fun project.
The closest thing I can think of for graphical rehauls is probably shader pack type stuff - Minecraft is a great example of this.
https://www.sonicether.com/seus