Wait, does the debugger work now? The last time I picked up Visual Studio code with a C# core project I couldn't' get the debugger to work with dnx web
The VS Code debugger supports a variety of languages. There is built in support for Node.js debugging which works really nicely. And there are extensions[0] providing support for: Go, PHP, Chrome, Unity and more.
The debugger for C# works on Windows only (for now, since the Linux/OSX debuggers will need to use gdb or lldb). Debuggers for other languages are supported by extensions. For instance, there's a javascript and Typescript debugger built in.