Didn't play, but the screenshot is looking great. BTW probably more people would test it if you offer it as a zip file that hasn't to be installed. Setup installation usually leave back some remains in registry and app folders, a thing people avoid. Additionally, when in XP user mode, a person first has to log in as admin, only to test your beta game.
So I'd say: development demos (well, demos adressed to other gamesdesigners) should only be zipped, releases for end customers should be a setup exe.
So I'd say: development demos (well, demos adressed to other gamesdesigners) should only be zipped, releases for end customers should be a setup exe.