It doesn't matter what language a game is written in to write an ESP for it. Any language will work as long as it can access the games memory, some sort of drawing API and such. Externally you can use ReadProcessMemory with GDI/GDI+ to draw onto the game. Internally you can hook the games engine drawing methods or the base engine stuff (Direct3D, OpenGL, etc.) and draw that way instead.
VB.NET can do both, but the work involved to do the latter is not really worth it. You are better off using C/C++ for things like this.