Hmm, I was hesitant on using ini since in C# there are zero ini readers. I'll have to P/Invoke it out of the core windows library, and I don't want to do that, ever. XML is 1000x easier to use under .NET, oh well. I'll have to construct or find an ini implementation that doesn't use P/Invoke... or at least is mono compatible. But I digress, I think I found one long ago, but never used it. Here it is: https://code.google.com/p/ini-parser/
It might be possible to change the icon of a packaged exe - even if it means somehow changing the icon of engine.exe.