Honestly, it's not worth marketing. You have a client based download of a game that people can play thousands of variants for free online.
First and foremost, you need to do something in flash. Unless you're doing a mobile game, or something in a heavy 3d engine, it's not worth making a client based game. Especially considering the amount of hurdles you're already putting in front of potential players (installing the .net framework etc..). Try out the flixel game engine (flash based). It lets you make games fast and easily.
Hope this helps.